Upgrading from 10 to 12.9 gives you 4.1 years worth of fixes (1345 of them)

List of changes:

• ⇑ Upgrade to 10.1 released on 2017-11-09 - docs

  • Ensure that INSERT ... ON CONFLICT DO UPDATE checks table permissions and RLS policies in all cases (Dean Rasheed)

    The update path of INSERT ... ON CONFLICT DO UPDATE requires SELECT permission on the columns of the arbiter index, but it failed to check for that in the case of an arbiter specified by constraint name. In addition, for a table with row level security enabled, it failed to check updated rows against the table's SELECT policies (regardless of how the arbiter index was specified). (CVE-2017-15099)

  • Fix crash due to rowtype mismatch in json{b}_populate_recordset() (Michael Paquier, Tom Lane)

    These functions used the result rowtype specified in the FROM ... AS clause without checking that it matched the actual rowtype of the supplied tuple value. If it didn't, that would usually result in a crash, though disclosure of server memory contents seems possible as well. (CVE-2017-15098)

  • Fix sample server-start scripts to become $PGUSER before opening $PGLOG (Noah Misch)

    Previously, the postmaster log file was opened while still running as root. The database owner could therefore mount an attack against another system user by making $PGLOG be a symbolic link to some other file, which would then become corrupted by appending log messages.

    By default, these scripts are not installed anywhere. Users who have made use of them will need to manually recopy them, or apply the same changes to their modified versions. If the existing $PGLOG file is root-owned, it will need to be removed or renamed out of the way before restarting the server with the corrected script. (CVE-2017-12172)

  • Fix BRIN index summarization to handle concurrent table extension correctly (Álvaro Herrera)

    Previously, a race condition allowed some table rows to be omitted from the index. It may be necessary to reindex existing BRIN indexes to recover from past occurrences of this problem.

  • Fix possible failures during concurrent updates of a BRIN index (Tom Lane)

    These race conditions could result in errors like “invalid index offnum” or “inconsistent range map”.

  • Prevent logical replication from setting non-replicated columns to nulls when replicating an UPDATE (Petr Jelinek)

  • Fix logical replication to fire BEFORE ROW DELETE triggers when expected (Masahiko Sawada)

    Previously, that failed to happen unless the table also had a BEFORE ROW UPDATE trigger.

  • Fix crash when logical decoding is invoked from a SPI-using function, in particular any function written in a PL language (Tom Lane)

  • Ignore CTEs when looking up the target table for INSERT/UPDATE/DELETE, and prevent matching schema-qualified target table names to trigger transition table names (Thomas Munro)

    This restores the pre-v10 behavior for CTEs attached to DML commands.

  • Avoid evaluating an aggregate function's argument expression(s) at rows where its FILTER test fails (Tom Lane)

    This restores the pre-v10 (and SQL-standard) behavior.

  • Fix incorrect query results when multiple GROUPING SETS columns contain the same simple variable (Tom Lane)

  • Fix query-lifespan memory leakage while evaluating a set-returning function in a SELECT's target list (Tom Lane)

  • Allow parallel execution of prepared statements with generic plans (Amit Kapila, Kuntal Ghosh)

  • Fix incorrect parallelization decisions for nested queries (Amit Kapila, Kuntal Ghosh)

  • Fix parallel query handling to not fail when a recently-used role is dropped (Amit Kapila)

  • Fix crash in parallel execution of a bitmap scan having a BitmapAnd plan node below a BitmapOr node (Dilip Kumar)

  • Fix json_build_array(), json_build_object(), and their jsonb equivalents to handle explicit VARIADIC arguments correctly (Michael Paquier)

  • Fix autovacuum's “work item” logic to prevent possible crashes and silent loss of work items (Álvaro Herrera)

  • Fix corner-case crashes when columns have been added to the end of a view (Tom Lane)

  • Record proper dependencies when a view or rule contains FieldSelect or FieldStore expression nodes (Tom Lane)

    Lack of these dependencies could allow a column or data type DROP to go through when it ought to fail, thereby causing later uses of the view or rule to get errors. This patch does not do anything to protect existing views/rules, only ones created in the future.

  • Correctly detect hashability of range data types (Tom Lane)

    The planner mistakenly assumed that any range type could be hashed for use in hash joins or hash aggregation, but actually it must check whether the range's subtype has hash support. This does not affect any of the built-in range types, since they're all hashable anyway.

  • Correctly ignore RelabelType expression nodes when examining functional-dependency statistics (David Rowley)

    This allows, e.g., extended statistics on varchar columns to be used properly.

  • Prevent sharing transition states between ordered-set aggregates (David Rowley)

    This causes a crash with the built-in ordered-set aggregates, and probably with user-written ones as well. v11 and later will include provisions for dealing with such cases safely, but in released branches, just disable the optimization.

  • Prevent idle_in_transaction_session_timeout from being ignored when a statement_timeout occurred earlier (Lukas Fittl)

  • Fix low-probability loss of NOTIFY messages due to XID wraparound (Marko Tiikkaja, Tom Lane)

    If a session executed no queries, but merely listened for notifications, for more than 2 billion transactions, it started to miss some notifications from concurrently-committing transactions.

  • Reduce the frequency of data flush requests during bulk file copies to avoid performance problems on macOS, particularly with its new APFS file system (Tom Lane)

  • Allow COPY's FREEZE option to work when the transaction isolation level is REPEATABLE READ or higher (Noah Misch)

    This case was unintentionally broken by a previous bug fix.

  • Fix AggGetAggref() to return the correct Aggref nodes to aggregate final functions whose transition calculations have been merged (Tom Lane)

  • Fix insufficient schema-qualification in some new queries in pg_dump and psql (Vitaly Burovoy, Tom Lane, Noah Misch)

  • Avoid use of @> operator in psql's queries for \d (Tom Lane)

    This prevents problems when the parray_gin extension is installed, since that defines a conflicting operator.

  • Fix pg_basebackup's matching of tablespace paths to canonicalize both paths before comparing (Michael Paquier)

    This is particularly helpful on Windows.

  • Fix libpq to not require user's home directory to exist (Tom Lane)

    In v10, failure to find the home directory while trying to read ~/.pgpass was treated as a hard error, but it should just cause that file to not be found. Both v10 and previous release branches made the same mistake when reading ~/.pg_service.conf, though this was less obvious since that file is not sought unless a service name is specified.

  • In ecpglib, correctly handle backslashes in string literals depending on whether standard_conforming_strings is set (Tsunakawa Takayuki)

  • Make ecpglib's Informix-compatibility mode ignore fractional digits in integer input strings, as expected (Gao Zengqi, Michael Meskes)

  • Fix missing temp-install prerequisites for check-like Make targets (Noah Misch)

    Some non-default test procedures that are meant to work like make check failed to ensure that the temporary installation was up to date.

  • Update time zone data files to tzdata release 2017c for DST law changes in Fiji, Namibia, Northern Cyprus, Sudan, Tonga, and Turks & Caicos Islands, plus historical corrections for Alaska, Apia, Burma, Calcutta, Detroit, Ireland, Namibia, and Pago Pago.

  • In the documentation, restore HTML anchors to being upper-case strings (Peter Eisentraut)

    Due to a toolchain change, the 10.0 user manual had lower-case strings for intrapage anchors, thus breaking some external links into our website documentation. Return to our previous convention of using upper-case strings.

• ⇑ Upgrade to 10.2 released on 2018-02-08 - docs

  • Fix processing of partition keys containing multiple expressions (Álvaro Herrera, David Rowley)

    This error led to crashes or, with carefully crafted input, disclosure of arbitrary backend memory. (CVE-2018-1052)

  • Ensure that all temporary files made by pg_upgrade are non-world-readable (Tom Lane, Noah Misch)

    pg_upgrade normally restricts its temporary files to be readable and writable only by the calling user. But the temporary file containing pg_dumpall -g output would be group- or world-readable, or even writable, if the user's umask setting allows. In typical usage on multi-user machines, the umask and/or the working directory's permissions would be tight enough to prevent problems; but there may be people using pg_upgrade in scenarios where this oversight would permit disclosure of database passwords to unfriendly eyes. (CVE-2018-1053)

  • Fix vacuuming of tuples that were updated while key-share locked (Andres Freund, Álvaro Herrera)

    In some cases VACUUM would fail to remove such tuples even though they are now dead, leading to assorted data corruption scenarios.

  • Fix failure to mark a hash index's metapage dirty after adding a new overflow page, potentially leading to index corruption (Lixian Zou, Amit Kapila)

  • Ensure that vacuum will always clean up the pending-insertions list of a GIN index (Masahiko Sawada)

    This is necessary to ensure that dead index entries get removed. The old code got it backwards, allowing vacuum to skip the cleanup if some other process were running cleanup concurrently, thus risking invalid entries being left behind in the index.

  • Fix inadequate buffer locking in some LSN fetches (Jacob Champion, Asim Praveen, Ashwin Agrawal)

    These errors could result in misbehavior under concurrent load. The potential consequences have not been characterized fully.

  • Fix incorrect query results from cases involving flattening of subqueries whose outputs are used in GROUPING SETS (Heikki Linnakangas)

  • Fix handling of list partitioning constraints for partition keys of boolean or array types (Amit Langote)

  • Avoid unnecessary failure in a query on an inheritance tree that occurs concurrently with some child table being removed from the tree by ALTER TABLE NO INHERIT (Tom Lane)

  • Fix spurious deadlock failures when multiple sessions are running CREATE INDEX CONCURRENTLY (Jeff Janes)

  • During VACUUM FULL, update the table's size fields in pg_class sooner (Amit Kapila)

    This prevents poor behavior when rebuilding hash indexes on the table, since those use the pg_class statistics to govern the initial hash size.

  • Fix UNION/INTERSECT/EXCEPT over zero columns (Tom Lane)

  • Disallow identity columns on typed tables and partitions (Michael Paquier)

    These cases will be treated as unsupported features for now.

  • Fix assorted failures to apply the correct default value when inserting into an identity column (Michael Paquier, Peter Eisentraut)

    In several contexts, notably COPY and ALTER TABLE ADD COLUMN, the expected default value was not applied and instead a null value was inserted.

  • Fix failures when an inheritance tree contains foreign child tables (Etsuro Fujita)

    A mix of regular and foreign tables in an inheritance tree resulted in creation of incorrect plans for UPDATE and DELETE queries. This led to visible failures in some cases, notably when there are row-level triggers on a foreign child table.

  • Repair failure with correlated sub-SELECT inside VALUES inside a LATERAL subquery (Tom Lane)

  • Fix “could not devise a query plan for the given query” planner failure for some cases involving nested UNION ALL inside a lateral subquery (Tom Lane)

  • Allow functional dependency statistics to be used for boolean columns (Tom Lane)

    Previously, although extended statistics could be declared and collected on boolean columns, the planner failed to apply them.

  • Avoid underestimating the number of groups emitted by subqueries containing set-returning functions in their grouping columns (Tom Lane)

    Cases similar to SELECT DISTINCT unnest(foo) got a lower output rowcount estimate in 10.0 than they did in earlier releases, possibly resulting in unfavorable plan choices. Restore the prior estimation behavior.

  • Fix use of triggers in logical replication workers (Petr Jelinek)

  • Fix logical decoding to correctly clean up disk files for crashed transactions (Atsushi Torikoshi)

    Logical decoding may spill WAL records to disk for transactions generating many WAL records. Normally these files are cleaned up after the transaction's commit or abort record arrives; but if no such record is ever seen, the removal code misbehaved.

  • Fix walsender timeout failure and failure to respond to interrupts when processing a large transaction (Petr Jelinek)

  • Fix race condition during replication origin drop that could allow the dropping process to wait indefinitely (Tom Lane)

  • Allow members of the pg_read_all_stats role to see walsender statistics in the pg_stat_replication view (Feike Steenbergen)

  • Show walsenders that are sending base backups as active in the pg_stat_activity view (Magnus Hagander)

  • Fix reporting of scram-sha-256 authentication method in the pg_hba_file_rules view (Michael Paquier)

    Previously this was printed as scram-sha256, possibly confusing users as to the correct spelling.

  • Fix has_sequence_privilege() to support WITH GRANT OPTION tests, as other privilege-testing functions do (Joe Conway)

  • In databases using UTF8 encoding, ignore any XML declaration that asserts a different encoding (Pavel Stehule, Noah Misch)

    We always store XML strings in the database encoding, so allowing libxml to act on a declaration of another encoding gave wrong results. In encodings other than UTF8, we don't promise to support non-ASCII XML data anyway, so retain the previous behavior for bug compatibility. This change affects only xpath() and related functions; other XML code paths already acted this way.

  • Provide for forward compatibility with future minor protocol versions (Robert Haas, Badrul Chowdhury)

    Up to now, PostgreSQL servers simply rejected requests to use protocol versions newer than 3.0, so that there was no functional difference between the major and minor parts of the protocol version number. Allow clients to request versions 3.x without failing, sending back a message showing that the server only understands 3.0. This makes no difference at the moment, but back-patching this change should allow speedier introduction of future minor protocol upgrades.

  • Allow a client that supports SCRAM channel binding (such as v11 or later libpq) to connect to a v10 server (Michael Paquier)

    v10 does not have this feature, and the connection-time negotiation about whether to use it was done incorrectly.

  • Avoid live-lock in ConditionVariableBroadcast() (Tom Lane, Thomas Munro)

    Given repeatedly-unlucky timing, a process attempting to awaken all waiters for a condition variable could loop indefinitely. Due to the limited usage of condition variables in v10, this affects only parallel index scans and some operations on replication slots.

  • Clean up waits for condition variables correctly during subtransaction abort (Robert Haas)

  • Ensure that child processes that are waiting for a condition variable will exit promptly if the postmaster process dies (Tom Lane)

  • Fix crashes in parallel queries using more than one Gather node (Thomas Munro)

  • Fix hang in parallel index scan when processing a deleted or half-dead index page (Amit Kapila)

  • Avoid crash if parallel bitmap heap scan is unable to allocate a shared memory segment (Robert Haas)

  • Cope with failure to start a parallel worker process (Amit Kapila, Robert Haas)

    Parallel query previously tended to hang indefinitely if a worker could not be started, as the result of fork() failure or other low-probability problems.

  • Avoid unnecessary failure when no parallel workers can be obtained during parallel query startup (Robert Haas)

  • Fix collection of EXPLAIN statistics from parallel workers (Amit Kapila, Thomas Munro)

  • Ensure that query strings passed to parallel workers are correctly null-terminated (Thomas Munro)

    This prevents emitting garbage in postmaster log output from such workers.

  • Avoid unsafe alignment assumptions when working with __int128 (Tom Lane)

    Typically, compilers assume that __int128 variables are aligned on 16-byte boundaries, but our memory allocation infrastructure isn't prepared to guarantee that, and increasing the setting of MAXALIGN seems infeasible for multiple reasons. Adjust the code to allow use of __int128 only when we can tell the compiler to assume lesser alignment. The only known symptom of this problem so far is crashes in some parallel aggregation queries.

  • Prevent stack-overflow crashes when planning extremely deeply nested set operations (UNION/INTERSECT/EXCEPT) (Tom Lane)

  • Avoid crash during an EvalPlanQual recheck of an indexscan that is the inner child of a merge join (Tom Lane)

    This could only happen during an update or SELECT FOR UPDATE of a join, when there is a concurrent update of some selected row.

  • Fix crash in autovacuum when extended statistics are defined for a table but can't be computed (Álvaro Herrera)

  • Fix null-pointer crashes for some types of LDAP URLs appearing in pg_hba.conf (Thomas Munro)

  • Prevent out-of-memory failures due to excessive growth of simple hash tables (Tomas Vondra, Andres Freund)

  • Fix sample INSTR() functions in the PL/pgSQL documentation (Yugo Nagata, Tom Lane)

    These functions are stated to be Oracle® compatible, but they weren't exactly. In particular, there was a discrepancy in the interpretation of a negative third parameter: Oracle thinks that a negative value indicates the last place where the target substring can begin, whereas our functions took it as the last place where the target can end. Also, Oracle throws an error for a zero or negative fourth parameter, whereas our functions returned zero.

    The sample code has been adjusted to match Oracle's behavior more precisely. Users who have copied this code into their applications may wish to update their copies.

  • Fix pg_dump to make ACL (permissions), comment, and security label entries reliably identifiable in archive output formats (Tom Lane)

    The “tag” portion of an ACL archive entry was usually just the name of the associated object. Make it start with the object type instead, bringing ACLs into line with the convention already used for comment and security label archive entries. Also, fix the comment and security label entries for the whole database, if present, to make their tags start with DATABASE so that they also follow this convention. This prevents false matches in code that tries to identify large-object-related entries by seeing if the tag starts with LARGE OBJECT. That could have resulted in misclassifying entries as data rather than schema, with undesirable results in a schema-only or data-only dump.

    Note that this change has user-visible results in the output of pg_restore --list.

  • Rename pg_rewind's copy_file_range function to avoid conflict with new Linux system call of that name (Andres Freund)

    This change prevents build failures with newer glibc versions.

  • In ecpg, detect indicator arrays that do not have the correct length and report an error (David Rader)

  • Change the behavior of contrib/cube's cube ~> int operator to make it compatible with KNN search (Alexander Korotkov)

    The meaning of the second argument (the dimension selector) has been changed to make it predictable which value is selected even when dealing with cubes of varying dimensionalities.

    This is an incompatible change, but since the point of the operator was to be used in KNN searches, it seems rather useless as-is. After installing this update, any expression indexes or materialized views using this operator will need to be reindexed/refreshed.

  • Avoid triggering a libc assertion in contrib/hstore, due to use of memcpy() with equal source and destination pointers (Tomas Vondra)

  • Fix incorrect display of tuples' null bitmaps in contrib/pageinspect (Maksim Milyutin)

  • Fix incorrect output from contrib/pageinspect's hash_page_items() function (Masahiko Sawada)

  • In contrib/postgres_fdw, avoid “outer pathkeys do not match mergeclauses” planner error when constructing a plan involving a remote join (Robert Haas)

  • In contrib/postgres_fdw, avoid planner failure when there are duplicate GROUP BY entries (Jeevan Chalke)

  • Provide modern examples of how to auto-start Postgres on macOS (Tom Lane)

    The scripts in contrib/start-scripts/osx use infrastructure that's been deprecated for over a decade, and which no longer works at all in macOS releases of the last couple of years. Add a new subdirectory contrib/start-scripts/macos containing scripts that use the newer launchd infrastructure.

  • Fix incorrect selection of configuration-specific libraries for OpenSSL on Windows (Andrew Dunstan)

  • Support linking to MinGW-built versions of libperl (Noah Misch)

    This allows building PL/Perl with some common Perl distributions for Windows.

  • Fix MSVC build to test whether 32-bit libperl needs -D_USE_32BIT_TIME_T (Noah Misch)

    Available Perl distributions are inconsistent about what they expect, and lack any reliable means of reporting it, so resort to a build-time test on what the library being used actually does.

  • On Windows, install the crash dump handler earlier in postmaster startup (Takayuki Tsunakawa)

    This may allow collection of a core dump for some early-startup failures that did not produce a dump before.

  • On Windows, avoid encoding-conversion-related crashes when emitting messages very early in postmaster startup (Takayuki Tsunakawa)

  • Use our existing Motorola 68K spinlock code on OpenBSD as well as NetBSD (David Carlier)

  • Add support for spinlocks on Motorola 88K (David Carlier)

  • Update time zone data files to tzdata release 2018c for DST law changes in Brazil, Sao Tome and Principe, plus historical corrections for Bolivia, Japan, and South Sudan. The US/Pacific-New zone has been removed (it was only an alias for America/Los_Angeles anyway).

• ⇑ Upgrade to 10.3 released on 2018-03-01 - docs

  • Document how to configure installations and applications to guard against search-path-dependent trojan-horse attacks from other users (Noah Misch)

    Using a search_path setting that includes any schemas writable by a hostile user enables that user to capture control of queries and then run arbitrary SQL code with the permissions of the attacked user. While it is possible to write queries that are proof against such hijacking, it is notationally tedious, and it's very easy to overlook holes. Therefore, we now recommend configurations in which no untrusted schemas appear in one's search path. Relevant documentation appears in Section 5.8.6 (for database administrators and users), Section 33.1 (for application authors), Section 37.15.1 (for extension authors), and CREATE FUNCTION (for authors of SECURITY DEFINER functions). (CVE-2018-1058)

  • Avoid use of insecure search_path settings in pg_dump and other client programs (Noah Misch, Tom Lane)

    pg_dump, pg_upgrade, vacuumdb and other PostgreSQL-provided applications were themselves vulnerable to the type of hijacking described in the previous changelog entry; since these applications are commonly run by superusers, they present particularly attractive targets. To make them secure whether or not the installation as a whole has been secured, modify them to include only the pg_catalog schema in their search_path settings. Autovacuum worker processes now do the same, as well.

    In cases where user-provided functions are indirectly executed by these programs — for example, user-provided functions in index expressions — the tighter search_path may result in errors, which will need to be corrected by adjusting those user-provided functions to not assume anything about what search path they are invoked under. That has always been good practice, but now it will be necessary for correct behavior. (CVE-2018-1058)

  • Prevent logical replication from trying to ship changes for unpublishable relations (Peter Eisentraut)

    A publication marked FOR ALL TABLES would incorrectly ship changes in materialized views and information_schema tables, which are supposed to be omitted from the change stream.

  • Fix misbehavior of concurrent-update rechecks with CTE references appearing in subplans (Tom Lane)

    If a CTE (WITH clause reference) is used in an InitPlan or SubPlan, and the query requires a recheck due to trying to update or lock a concurrently-updated row, incorrect results could be obtained.

  • Fix planner failures with overlapping mergejoin clauses in an outer join (Tom Lane)

    These mistakes led to “left and right pathkeys do not match in mergejoin” or “outer pathkeys do not match mergeclauses” planner errors in corner cases.

  • Repair pg_upgrade's failure to preserve relfrozenxid for materialized views (Tom Lane, Andres Freund)

    This oversight could lead to data corruption in materialized views after an upgrade, manifesting as “could not access status of transaction” or “found xmin from before relfrozenxid” errors. The problem would be more likely to occur in seldom-refreshed materialized views, or ones that were maintained only with REFRESH MATERIALIZED VIEW CONCURRENTLY.

    If such corruption is observed, it can be repaired by refreshing the materialized view (without CONCURRENTLY).

  • Fix incorrect pg_dump output for some non-default sequence limit values (Alexey Bashtanov)

  • Fix pg_dump's mishandling of STATISTICS objects (Tom Lane)

    An extended statistics object's schema was mislabeled in the dump's table of contents, possibly leading to the wrong results in a schema-selective restore. Its ownership was not correctly restored, either. Also, change the logic so that statistics objects are dumped/restored, or not, as independent objects rather than tying them to the dump/restore decision for the table they are on. The original definition could not scale to the planned future extension to cross-table statistics.

  • Fix incorrect reporting of PL/Python function names in error CONTEXT stacks (Tom Lane)

    An error occurring within a nested PL/Python function call (that is, one reached via a SPI query from another PL/Python function) would result in a stack trace showing the inner function's name twice, rather than the expected results. Also, an error in a nested PL/Python DO block could result in a null pointer dereference crash on some platforms.

  • Allow contrib/auto_explain's log_min_duration setting to range up to INT_MAX, or about 24 days instead of 35 minutes (Tom Lane)

  • Mark assorted GUC variables as PGDLLIMPORT, to ease porting extension modules to Windows (Metin Doslu)

• ⇑ Upgrade to 10.4 released on 2018-05-10 - docs

  • Remove public execute privilege from contrib/adminpack's pg_logfile_rotate() function (Stephen Frost)

    pg_logfile_rotate() is a deprecated wrapper for the core function pg_rotate_logfile(). When that function was changed to rely on SQL privileges for access control rather than a hard-coded superuser check, pg_logfile_rotate() should have been updated as well, but the need for this was missed. Hence, if adminpack is installed, any user could request a logfile rotation, creating a minor security issue.

    After installing this update, administrators should update adminpack by performing ALTER EXTENSION adminpack UPDATE in each database in which adminpack is installed. (CVE-2018-1115)

  • Fix incorrect volatility markings on a few built-in functions (Thomas Munro, Tom Lane)

    The functions query_to_xml, cursor_to_xml, cursor_to_xmlschema, query_to_xmlschema, and query_to_xml_and_xmlschema should be marked volatile because they execute user-supplied queries that might contain volatile operations. They were not, leading to a risk of incorrect query optimization. This has been repaired for new installations by correcting the initial catalog data, but existing installations will continue to contain the incorrect markings. Practical use of these functions seems to pose little hazard, but in case of trouble, it can be fixed by manually updating these functions' pg_proc entries, for example ALTER FUNCTION pg_catalog.query_to_xml(text, boolean, boolean, text) VOLATILE. (Note that that will need to be done in each database of the installation.) Another option is to pg_upgrade the database to a version containing the corrected initial data.

  • Fix incorrect parallel-safety markings on a few built-in functions (Thomas Munro, Tom Lane)

    The functions brin_summarize_new_values, brin_summarize_range, brin_desummarize_range, gin_clean_pending_list, cursor_to_xml, cursor_to_xmlschema, ts_rewrite, ts_stat, binary_upgrade_create_empty_extension, and pg_import_system_collations should be marked parallel-unsafe; some because they perform database modifications directly, and others because they execute user-supplied queries that might do so. They were marked parallel-restricted instead, leading to a risk of unexpected query errors. This has been repaired for new installations by correcting the initial catalog data, but existing installations will continue to contain the incorrect markings. Practical use of these functions seems to pose little hazard unless force_parallel_mode is turned on. In case of trouble, it can be fixed by manually updating these functions' pg_proc entries, for example ALTER FUNCTION pg_catalog.brin_summarize_new_values(regclass) PARALLEL UNSAFE. (Note that that will need to be done in each database of the installation.) Another option is to pg_upgrade the database to a version containing the corrected initial data.

  • Avoid re-using TOAST value OIDs that match dead-but-not-yet-vacuumed TOAST entries (Pavan Deolasee)

    Once the OID counter has wrapped around, it's possible to assign a TOAST value whose OID matches a previously deleted entry in the same TOAST table. If that entry were not yet vacuumed away, this resulted in “unexpected chunk number 0 (expected 1) for toast value nnnnn” errors, which would persist until the dead entry was removed by VACUUM. Fix by not selecting such OIDs when creating a new TOAST entry.

  • Correctly enforce any CHECK constraints on individual partitions during COPY to a partitioned table (Etsuro Fujita)

    Previously, only constraints declared for the partitioned table as a whole were checked.

  • Accept TRUE and FALSE as partition bound values (Amit Langote)

    Previously, only string-literal values were accepted for a boolean partitioning column. But then pg_dump would print such values as TRUE or FALSE, leading to dump/reload failures.

  • Fix memory management for partition key comparison functions (Álvaro Herrera, Amit Langote)

    This error could lead to crashes when using user-defined operator classes for partition keys.

  • Fix possible crash when a query inserts tuples in several partitions of a partitioned table, and those partitions don't have identical row types (Etsuro Fujita, Amit Langote)

  • Change ANALYZE's algorithm for updating pg_class.reltuples (David Gould)

    Previously, pages not actually scanned by ANALYZE were assumed to retain their old tuple density. In a large table where ANALYZE samples only a small fraction of the pages, this meant that the overall tuple density estimate could not change very much, so that reltuples would change nearly proportionally to changes in the table's physical size (relpages) regardless of what was actually happening in the table. This has been observed to result in reltuples becoming so much larger than reality as to effectively shut off autovacuuming. To fix, assume that ANALYZE's sample is a statistically unbiased sample of the table (as it should be), and just extrapolate the density observed within those pages to the whole table.

  • Include extended-statistics objects in the set of table properties duplicated by CREATE TABLE ... LIKE ... INCLUDING ALL (David Rowley)

    Also add an INCLUDING STATISTICS option, to allow finer-grained control over whether this happens.

  • Fix CREATE TABLE ... LIKE with bigint identity columns (Peter Eisentraut)

    On platforms where long is 32 bits (which includes 64-bit Windows as well as most 32-bit machines), copied sequence parameters would be truncated to 32 bits.

  • Avoid deadlocks in concurrent CREATE INDEX CONCURRENTLY commands that are run under SERIALIZABLE or REPEATABLE READ transaction isolation (Tom Lane)

  • Fix possible slow execution of REFRESH MATERIALIZED VIEW CONCURRENTLY (Thomas Munro)

  • Fix UPDATE/DELETE ... WHERE CURRENT OF to not fail when the referenced cursor uses an index-only-scan plan (Yugo Nagata, Tom Lane)

  • Fix incorrect planning of join clauses pushed into parameterized paths (Andrew Gierth, Tom Lane)

    This error could result in misclassifying a condition as a “join filter” for an outer join when it should be a plain “filter” condition, leading to incorrect join output.

  • Fix possibly incorrect generation of an index-only-scan plan when the same table column appears in multiple index columns, and only some of those index columns use operator classes that can return the column value (Kyotaro Horiguchi)

  • Fix misoptimization of CHECK constraints having provably-NULL subclauses of top-level AND/OR conditions (Tom Lane, Dean Rasheed)

    This could, for example, allow constraint exclusion to exclude a child table that should not be excluded from a query.

  • Prevent planner crash when a query has multiple GROUPING SETS, none of which can be implemented by sorting (Andrew Gierth)

  • Fix executor crash due to double free in some GROUPING SETS usages (Peter Geoghegan)

  • Fix misexecution of self-joins on transition tables (Thomas Munro)

  • Avoid crash if a table rewrite event trigger is added concurrently with a command that could call such a trigger (Álvaro Herrera, Andrew Gierth, Tom Lane)

  • Avoid failure if a query-cancel or session-termination interrupt occurs while committing a prepared transaction (Stas Kelvich)

  • Fix query-lifespan memory leakage in repeatedly executed hash joins (Tom Lane)

  • Fix possible leak or double free of visibility map buffer pins (Amit Kapila)

  • Avoid spuriously marking pages as all-visible (Dan Wood, Pavan Deolasee, Álvaro Herrera)

    This could happen if some tuples were locked (but not deleted). While queries would still function correctly, vacuum would normally ignore such pages, with the long-term effect that the tuples were never frozen. In recent releases this would eventually result in errors such as “found multixact nnnnn from before relminmxid nnnnn”.

  • Fix overly strict sanity check in heap_prepare_freeze_tuple (Álvaro Herrera)

    This could result in incorrect “cannot freeze committed xmax” failures in databases that have been pg_upgrade'd from 9.2 or earlier.

  • Prevent dangling-pointer dereference when a C-coded before-update row trigger returns the “old” tuple (Rushabh Lathia)

  • Reduce locking during autovacuum worker scheduling (Jeff Janes)

    The previous behavior caused drastic loss of potential worker concurrency in databases with many tables.

  • Ensure client hostname is copied while copying pg_stat_activity data to local memory (Edmund Horner)

    Previously the supposedly-local snapshot contained a pointer into shared memory, allowing the client hostname column to change unexpectedly if any existing session disconnected.

  • Handle pg_stat_activity information for auxiliary processes correctly (Edmund Horner)

    The application_name, client_hostname, and query fields might show incorrect data for such processes.

  • Fix incorrect processing of multiple compound affixes in ispell dictionaries (Arthur Zakirov)

  • Fix collation-aware searches (that is, indexscans using inequality operators) in SP-GiST indexes on text columns (Tom Lane)

    Such searches would return the wrong set of rows in most non-C locales.

  • Prevent query-lifespan memory leakage with SP-GiST operator classes that use traversal values (Anton Dignös)

  • Count the number of index tuples correctly during initial build of an SP-GiST index (Tomas Vondra)

    Previously, the tuple count was reported to be the same as that of the underlying table, which is wrong if the index is partial.

  • Count the number of index tuples correctly during vacuuming of a GiST index (Andrey Borodin)

    Previously it reported the estimated number of heap tuples, which might be inaccurate, and is certainly wrong if the index is partial.

  • Fix a corner case where a streaming standby gets stuck at a WAL continuation record (Kyotaro Horiguchi)

  • In logical decoding, avoid possible double processing of WAL data when a walsender restarts (Craig Ringer)

  • Fix logical replication to not assume that type OIDs match between the local and remote servers (Masahiko Sawada)

  • Allow scalarltsel and scalargtsel to be used on non-core datatypes (Tomas Vondra)

  • Reduce libpq's memory consumption when a server error is reported after a large amount of query output has been collected (Tom Lane)

    Discard the previous output before, not after, processing the error message. On some platforms, notably Linux, this can make a difference in the application's subsequent memory footprint.

  • Fix double-free crashes in ecpg (Patrick Krecker, Jeevan Ladhe)

  • Fix ecpg to handle long long int variables correctly in MSVC builds (Michael Meskes, Andrew Gierth)

  • Fix mis-quoting of values for list-valued GUC variables in dumps (Michael Paquier, Tom Lane)

    The local_preload_libraries, session_preload_libraries, shared_preload_libraries, and temp_tablespaces variables were not correctly quoted in pg_dump output. This would cause problems if settings for these variables appeared in CREATE FUNCTION ... SET or ALTER DATABASE/ROLE ... SET clauses.

  • Fix pg_recvlogical to not fail against pre-v10 PostgreSQL servers (Michael Paquier)

    A previous fix caused pg_recvlogical to issue a command regardless of server version, but it should only be issued to v10 and later servers.

  • Ensure that pg_rewind deletes files on the target server if they are deleted from the source server during the run (Takayuki Tsunakawa)

    Failure to do this could result in data inconsistency on the target, particularly if the file in question is a WAL segment.

  • Fix pg_rewind to handle tables in non-default tablespaces correctly (Takayuki Tsunakawa)

  • Fix overflow handling in PL/pgSQL integer FOR loops (Tom Lane)

    The previous coding failed to detect overflow of the loop variable on some non-gcc compilers, leading to an infinite loop.

  • Adjust PL/Python regression tests to pass under Python 3.7 (Peter Eisentraut)

  • Support testing PL/Python and related modules when building with Python 3 and MSVC (Andrew Dunstan)

  • Fix errors in initial build of contrib/bloom indexes (Tomas Vondra, Tom Lane)

    Fix possible omission of the table's last tuple from the index. Count the number of index tuples correctly, in case it is a partial index.

  • Rename internal b64_encode and b64_decode functions to avoid conflict with Solaris 11.4 built-in functions (Rainer Orth)

  • Sync our copy of the timezone library with IANA tzcode release 2018e (Tom Lane)

    This fixes the zic timezone data compiler to cope with negative daylight-savings offsets. While the PostgreSQL project will not immediately ship such timezone data, zic might be used with timezone data obtained directly from IANA, so it seems prudent to update zic now.

  • Update time zone data files to tzdata release 2018d for DST law changes in Palestine and Antarctica (Casey Station), plus historical corrections for Portugal and its colonies, as well as Enderbury, Jamaica, Turks & Caicos Islands, and Uruguay.

• ⇑ Upgrade to 10.5 released on 2018-08-09 - docs

  • Fix failure to reset libpq's state fully between connection attempts (Tom Lane)

    An unprivileged user of dblink or postgres_fdw could bypass the checks intended to prevent use of server-side credentials, such as a ~/.pgpass file owned by the operating-system user running the server. Servers allowing peer authentication on local connections are particularly vulnerable. Other attacks such as SQL injection into a postgres_fdw session are also possible. Attacking postgres_fdw in this way requires the ability to create a foreign server object with selected connection parameters, but any user with access to dblink could exploit the problem. In general, an attacker with the ability to select the connection parameters for a libpq-using application could cause mischief, though other plausible attack scenarios are harder to think of. Our thanks to Andrew Krasichkov for reporting this issue. (CVE-2018-10915)

  • Fix INSERT ... ON CONFLICT UPDATE through a view that isn't just SELECT * FROM ... (Dean Rasheed, Amit Langote)

    Erroneous expansion of an updatable view could lead to crashes or “attribute ... has the wrong type” errors, if the view's SELECT list doesn't match one-to-one with the underlying table's columns. Furthermore, this bug could be leveraged to allow updates of columns that an attacking user lacks UPDATE privilege for, if that user has INSERT and UPDATE privileges for some other column(s) of the table. Any user could also use it for disclosure of server memory. (CVE-2018-10925)

  • Ensure that updates to the relfrozenxid and relminmxid values for “nailed” system catalogs are processed in a timely fashion (Andres Freund)

    Overoptimistic caching rules could prevent these updates from being seen by other sessions, leading to spurious errors and/or data corruption. The problem was significantly worse for shared catalogs, such as pg_authid, because the stale cache data could persist into new sessions as well as existing ones.

  • Fix case where a freshly-promoted standby crashes before having completed its first post-recovery checkpoint (Michael Paquier, Kyotaro Horiguchi, Pavan Deolasee, Álvaro Herrera)

    This led to a situation where the server did not think it had reached a consistent database state during subsequent WAL replay, preventing restart.

  • Avoid emitting a bogus WAL record when recycling an all-zero btree page (Amit Kapila)

    This mistake has been seen to cause assertion failures, and potentially it could result in unnecessary query cancellations on hot standby servers.

  • During WAL replay, guard against corrupted record lengths exceeding 1GB (Michael Paquier)

    Treat such a case as corrupt data. Previously, the code would try to allocate space and get a hard error, making recovery impossible.

  • When ending recovery, delay writing the timeline history file as long as possible (Heikki Linnakangas)

    This avoids some situations where a failure during recovery cleanup (such as a problem with a two-phase state file) led to inconsistent timeline state on-disk.

  • Improve performance of WAL replay for transactions that drop many relations (Fujii Masao)

    This change reduces the number of times that shared buffers are scanned, so that it is of most benefit when that setting is large.

  • Improve performance of lock releasing in standby server WAL replay (Thomas Munro)

  • Make logical WAL senders report streaming state correctly (Simon Riggs, Sawada Masahiko)

    The code previously mis-detected whether or not it had caught up with the upstream server.

  • Ensure that a snapshot is provided when executing data type input functions in logical replication subscribers (Minh-Quan Tran, Álvaro Herrera)

    This omission led to failures in some cases, such as domains with constraints using SQL-language functions.

  • Fix bugs in snapshot handling during logical decoding, allowing wrong decoding results in rare cases (Arseny Sher, Álvaro Herrera)

  • Add subtransaction handling in logical-replication table synchronization workers (Amit Khandekar, Robert Haas)

    Previously, table synchronization could misbehave if any subtransactions were aborted after modifying a table being synchronized.

  • Ensure a table's cached index list is correctly rebuilt after an index creation fails partway through (Peter Geoghegan)

    Previously, the failed index's OID could remain in the list, causing problems later in the same session.

  • Fix mishandling of empty uncompressed posting list pages in GIN indexes (Sivasubramanian Ramasubramanian, Alexander Korotkov)

    This could result in an assertion failure after pg_upgrade of a pre-9.4 GIN index (9.4 and later will not create such pages).

  • Pad arrays of unnamed POSIX semaphores to reduce cache line sharing (Thomas Munro)

    This reduces contention on many-CPU systems, fixing a performance regression (compared to previous releases) on Linux and FreeBSD.

  • Ensure that a process doing a parallel index scan will respond to signals (Amit Kapila)

    Previously, parallel workers could get stuck waiting for a lock on an index page, and not notice requests to abort the query.

  • Ensure that VACUUM will respond to signals within btree page deletion loops (Andres Freund)

    Corrupted btree indexes could result in an infinite loop here, and that previously wasn't interruptible without forcing a crash.

  • Fix hash-join costing mistake introduced with inner_unique optimization (David Rowley)

    This could lead to bad plan choices in situations where that optimization was applicable.

  • Fix misoptimization of equivalence classes involving composite-type columns (Tom Lane)

    This resulted in failure to recognize that an index on a composite column could provide the sort order needed for a mergejoin on that column.

  • Fix planner to avoid “ORDER/GROUP BY expression not found in targetlist” errors in some queries with set-returning functions (Tom Lane)

  • Fix handling of partition keys whose data type uses a polymorphic btree operator class, such as arrays (Amit Langote, Álvaro Herrera)

  • Fix SQL-standard FETCH FIRST syntax to allow parameters ($n), as the standard expects (Andrew Gierth)

  • Remove undocumented restriction against duplicate partition key columns (Yugo Nagata)

  • Disallow temporary tables from being partitions of non-temporary tables (Amit Langote, Michael Paquier)

    While previously allowed, this case didn't work reliably.

  • Fix EXPLAIN's accounting for resource usage, particularly buffer accesses, in parallel workers (Amit Kapila, Robert Haas)

  • Fix SHOW ALL to show all settings to roles that are members of pg_read_all_settings, and also allow such roles to see source filename and line number in the pg_settings view (Laurenz Albe, Álvaro Herrera)

  • Fix failure to schema-qualify some object names in getObjectDescription and getObjectIdentity output (Kyotaro Horiguchi, Tom Lane)

    Names of collations, conversions, text search objects, publication relations, and extended statistics objects were not schema-qualified when they should be.

  • Fix CREATE AGGREGATE type checking so that parallelism support functions can be attached to variadic aggregates (Alexey Bashtanov)

  • Widen COPY FROM's current-line-number counter from 32 to 64 bits (David Rowley)

    This avoids two problems with input exceeding 4G lines: COPY FROM WITH HEADER would drop a line every 4G lines, not only the first line, and error reports could show a wrong line number.

  • Allow replication slots to be dropped in single-user mode (Álvaro Herrera)

    This use-case was accidentally broken in release 10.0.

  • Fix incorrect results from variance(int4) and related aggregates when run in parallel aggregation mode (David Rowley)

  • Process TEXT and CDATA nodes correctly in xmltable() column expressions (Markus Winand)

  • Cope with possible failure of OpenSSL's RAND_bytes() function (Dean Rasheed, Michael Paquier)

    Under rare circumstances, this oversight could result in “could not generate random cancel key” failures that could only be resolved by restarting the postmaster.

  • Fix libpq's handling of some cases where hostaddr is specified (Hari Babu, Tom Lane, Robert Haas)

    PQhost() gave misleading or incorrect results in some cases. Now, it uniformly returns the host name if specified, or the host address if only that is specified, or the default host name (typically /tmp or localhost) if both parameters are omitted.

    Also, the wrong value might be compared to the server name when verifying an SSL certificate.

    Also, the wrong value might be compared to the host name field in ~/.pgpass. Now, that field is compared to the host name if specified, or the host address if only that is specified, or localhost if both parameters are omitted.

    Also, an incorrect error message was reported for an unparseable hostaddr value.

    Also, when the host, hostaddr, or port parameters contain comma-separated lists, libpq is now more careful to treat empty elements of a list as selecting the default behavior.

  • Add a string freeing function to ecpg's pgtypes library, so that cross-module memory management problems can be avoided on Windows (Takayuki Tsunakawa)

    On Windows, crashes can ensue if the free call for a given chunk of memory is not made from the same DLL that malloc'ed the memory. The pgtypes library sometimes returns strings that it expects the caller to free, making it impossible to follow this rule. Add a PGTYPESchar_free() function that just wraps free, allowing applications to follow this rule.

  • Fix ecpg's support for long long variables on Windows, as well as other platforms that declare strtoll/strtoull nonstandardly or not at all (Dang Minh Huong, Tom Lane)

  • Fix misidentification of SQL statement type in PL/pgSQL, when a rule change causes a change in the semantics of a statement intra-session (Tom Lane)

    This error led to assertion failures, or in rare cases, failure to enforce the INTO STRICT option as expected.

  • Fix password prompting in client programs so that echo is properly disabled on Windows when stdin is not the terminal (Matthew Stickney)

  • Further fix mis-quoting of values for list-valued GUC variables in dumps (Tom Lane)

    The previous fix for quoting of search_path and other list-valued variables in pg_dump output turned out to misbehave for empty-string list elements, and it risked truncation of long file paths.

  • Fix pg_dump's failure to dump REPLICA IDENTITY properties for constraint indexes (Tom Lane)

    Manually created unique indexes were properly marked, but not those created by declaring UNIQUE or PRIMARY KEY constraints.

  • Make pg_upgrade check that the old server was shut down cleanly (Bruce Momjian)

    The previous check could be fooled by an immediate-mode shutdown.

  • Fix contrib/hstore_plperl to look through Perl scalar references, and to not crash if it doesn't find a hash reference where it expects one (Tom Lane)

  • Fix crash in contrib/ltree's lca() function when the input array is empty (Pierre Ducroquet)

  • Fix various error-handling code paths in which an incorrect error code might be reported (Michael Paquier, Tom Lane, Magnus Hagander)

  • Rearrange makefiles to ensure that programs link to freshly-built libraries (such as libpq.so) rather than ones that might exist in the system library directories (Tom Lane)

    This avoids problems when building on platforms that supply old copies of PostgreSQL libraries.

  • Update time zone data files to tzdata release 2018e for DST law changes in North Korea, plus historical corrections for Czechoslovakia.

    This update includes a redefinition of “daylight savings” in Ireland, as well as for some past years in Namibia and Czechoslovakia. In those jurisdictions, legally standard time is observed in summer, and daylight savings time in winter, so that the daylight savings offset is one hour behind standard time not one hour ahead. This does not affect either the actual UTC offset or the timezone abbreviations in use; the only known effect is that the is_dst column in the pg_timezone_names view will now be true in winter and false in summer in these cases.

• ⇑ Upgrade to 11 released on 2018-10-18 - docs

  • Make pg_dump dump the properties of a database, not just its contents (Haribabu Kommi)

    Previously, attributes of the database itself, such as database-level GRANT/REVOKE permissions and ALTER DATABASE SET variable settings, were only dumped by pg_dumpall. Now pg_dump --create and pg_restore --create will restore these database properties in addition to the objects within the database. pg_dumpall -g now only dumps role- and tablespace-related attributes. pg_dumpall's complete output (without -g) is unchanged.

    pg_dump and pg_restore, without --create, no longer dump/restore database-level comments and security labels; those are now treated as properties of the database.

    pg_dumpall's output script will now always create databases with their original locale and encoding, and hence will fail if the locale or encoding name is unknown to the destination system. Previously, CREATE DATABASE would be emitted without these specifications if the database locale and encoding matched the old cluster's defaults.

    pg_dumpall --clean now restores the original locale and encoding settings of the postgres and template1 databases, as well as those of user-created databases.

  • Consider syntactic form when disambiguating function versus column references (Tom Lane)

    When x is a table name or composite column, PostgreSQL has traditionally considered the syntactic forms f(x) and x.f to be equivalent, allowing tricks such as writing a function and then using it as though it were a computed-on-demand column. However, if both interpretations are feasible, the column interpretation was always chosen, leading to surprising results if the user intended the function interpretation. Now, if there is ambiguity, the interpretation that matches the syntactic form is chosen.

  • Fully enforce uniqueness of table and domain constraint names (Tom Lane)

    PostgreSQL expects the names of a table's constraints to be distinct, and likewise for the names of a domain's constraints. However, there was not rigid enforcement of this, and previously there were corner cases where duplicate names could be created.

  • Make power(numeric, numeric) and power(float8, float8) handle NaN inputs according to the POSIX standard (Tom Lane, Dang Minh Huong)

    POSIX says that NaN ^ 0 = 1 and 1 ^ NaN = 1, but all other cases with NaN input(s) should return NaN. power(numeric, numeric) just returned NaN in all such cases; now it honors the two exceptions. power(float8, float8) followed the standard if the C library does; but on some old Unix platforms the library doesn't, and there were also problems on some versions of Windows.

  • Prevent to_number() from consuming characters when the template separator does not match (Oliver Ford)

    Specifically, SELECT to_number('1234', '9,999') used to return 134. It will now return 1234. L and TH now only consume characters that are not digits, positive/negative signs, decimal points, or commas.

  • Fix to_date(), to_number(), and to_timestamp() to skip a character for each template character (Tom Lane)

    Previously, they skipped one byte for each byte of template character, resulting in strange behavior if either string contained multibyte characters.

  • Adjust the handling of backslashes inside double-quotes in template strings for to_char(), to_number(), and to_timestamp().

    Such a backslash now escapes the character after it, particularly a double-quote or another backslash.

  • Correctly handle relative path expressions in xmltable(), xpath(), and other XML-handling functions (Markus Winand)

    Per the SQL standard, relative paths start from the document node of the XML input document, not the root node as these functions previously did.

  • In the extended query protocol, make statement_timeout apply to each Execute message separately, not to all commands before Sync (Tatsuo Ishii, Andres Freund)

  • Remove the relhaspkey column from system catalog pg_class (Peter Eisentraut)

    Applications needing to check for a primary key should consult pg_index.

  • Replace system catalog pg_proc's proisagg and proiswindow columns with prokind (Peter Eisentraut)

    This new column more clearly distinguishes functions, procedures, aggregates, and window functions.

  • Correct information schema column tables.table_type to return FOREIGN instead of FOREIGN TABLE (Peter Eisentraut)

    This new output matches the SQL standard.

  • Change the ps process display labels for background workers to match the pg_stat_activity.backend_type labels (Peter Eisentraut)

  • Cause large object permission checks to happen during large object open, lo_open(), not when a read or write is attempted (Tom Lane, Michael Paquier)

    If write access is requested and not available, an error will now be thrown even if the large object is never written to.

  • Prevent non-superusers from reindexing shared catalogs (Michael Paquier, Robert Haas)

    Previously, database owners were also allowed to do this, but now it is considered outside the bounds of their privileges.

  • Remove deprecated adminpack functions pg_file_read(), pg_file_length(), and pg_logfile_rotate() (Stephen Frost)

    Equivalent functionality is now present in the core backend. Existing adminpack installs will continue to have access to these functions until they are updated via ALTER EXTENSION ... UPDATE.

  • Honor the capitalization of double-quoted command options (Daniel Gustafsson)

    Previously, option names in certain SQL commands were forcibly lower-cased even if entered with double quotes; thus for example "FillFactor" would be accepted as an index storage option, though properly its name is lower-case. Such cases will now generate an error.

  • Remove server parameter replacement_sort_tuples (Peter Geoghegan)

    Replacement sorts were determined to be no longer useful.

  • Remove WITH clause in CREATE FUNCTION (Michael Paquier)

    PostgreSQL has long supported a more standard-compliant syntax for this capability.

  • In PL/pgSQL trigger functions, the OLD and NEW variables now read as NULL when not assigned (Tom Lane)

    Previously, references to these variables could be parsed but not executed.

  • Allow the creation of partitions based on hashing a key column (Amul Sul)

  • Support indexes on partitioned tables (Álvaro Herrera, Amit Langote)

    An “index” on a partitioned table is not a physical index across the whole partitioned table, but rather a template for automatically creating similar indexes on each partition of the table.

    If the partition key is part of the index's column set, a partitioned index may be declared UNIQUE. It will represent a valid uniqueness constraint across the whole partitioned table, even though each physical index only enforces uniqueness within its own partition.

    The new command ALTER INDEX ATTACH PARTITION causes an existing index on a partition to be associated with a matching index template for its partitioned table. This provides flexibility in setting up a new partitioned index for an existing partitioned table.

  • Allow foreign keys on partitioned tables (Álvaro Herrera)

  • Allow FOR EACH ROW triggers on partitioned tables (Álvaro Herrera)

    Creation of a trigger on a partitioned table automatically creates triggers on all existing and future partitions. This also allows deferred unique constraints on partitioned tables.

  • Allow partitioned tables to have a default partition (Jeevan Ladhe, Beena Emerson, Ashutosh Bapat, Rahila Syed, Robert Haas)

    The default partition will store rows that don't match any of the other defined partitions, and is searched accordingly.

  • UPDATE statements that change a partition key column now cause affected rows to be moved to the appropriate partitions (Amit Khandekar)

  • Allow INSERT, UPDATE, and COPY on partitioned tables to properly route rows to foreign partitions (Etsuro Fujita, Amit Langote)

    This is supported by postgres_fdw foreign tables. Since the ExecForeignInsert callback function is called for this in a different way than it used to be, foreign data wrappers must be modified to cope with this change.

  • Allow faster partition elimination during query processing (Amit Langote, David Rowley, Dilip Kumar)

    This speeds access to partitioned tables with many partitions.

  • Allow partition elimination during query execution (David Rowley, Beena Emerson)

    Previously, partition elimination only happened at planning time, meaning many joins and prepared queries could not use partition elimination.

  • In an equality join between partitioned tables, allow matching partitions to be joined directly (Ashutosh Bapat)

    This feature is disabled by default but can be enabled by changing enable_partitionwise_join.

  • Allow aggregate functions on partitioned tables to be evaluated separately for each partition, subsequently merging the results (Jeevan Chalke, Ashutosh Bapat, Robert Haas)

    This feature is disabled by default but can be enabled by changing enable_partitionwise_aggregate.

  • Allow postgres_fdw to push down aggregates to foreign tables that are partitions (Jeevan Chalke)

  • Allow parallel building of a btree index (Peter Geoghegan, Rushabh Lathia, Heikki Linnakangas)

  • Allow hash joins to be performed in parallel using a shared hash table (Thomas Munro)

  • Allow UNION to run each SELECT in parallel if the individual SELECTs cannot be parallelized (Amit Khandekar, Robert Haas, Amul Sul)

  • Allow partition scans to more efficiently use parallel workers (Amit Khandekar, Robert Haas, Amul Sul)

  • Allow LIMIT to be passed to parallel workers (Robert Haas, Tom Lane)

    This allows workers to reduce returned results and use targeted index scans.

  • Allow single-evaluation queries, e.g. WHERE clause aggregate queries, and functions in the target list to be parallelized (Amit Kapila, Robert Haas)

  • Add server parameter parallel_leader_participation to control whether the leader also executes subplans (Thomas Munro)

    The default is enabled, meaning the leader will execute subplans.

  • Allow parallelization of commands CREATE TABLE ... AS, SELECT INTO, and CREATE MATERIALIZED VIEW (Haribabu Kommi)

  • Improve performance of sequential scans with many parallel workers (David Rowley)

  • Add reporting of parallel workers' sort activity in EXPLAIN (Robert Haas, Tom Lane)

  • Allow B-tree indexes to include columns that are not part of the search key or unique constraint, but are available to be read by index-only scans (Anastasia Lubennikova, Alexander Korotkov, Teodor Sigaev)

    This is enabled by the new INCLUDE clause of CREATE INDEX. It facilitates building “covering indexes” that optimize specific types of queries. Columns can be included even if their data types don't have B-tree support.

  • Improve performance of monotonically increasing index additions (Pavan Deolasee, Peter Geoghegan)

  • Improve performance of hash index scans (Ashutosh Sharma)

  • Add predicate locking for hash, GiST and GIN indexes (Shubham Barai)

    This reduces the likelihood of serialization conflicts in serializable-mode transactions.

  • Add prefix-match operator text ^@ text, which is supported by SP-GiST (Ildus Kurbangaliev)

    This is similar to using var LIKE 'word%' with a btree index, but it is more efficient.

  • Allow polygons to be indexed with SP-GiST (Nikita Glukhov, Alexander Korotkov)

  • Allow SP-GiST to use lossy representation of leaf keys (Teodor Sigaev, Heikki Linnakangas, Alexander Korotkov, Nikita Glukhov)

  • Improve selection of the most common values for statistics (Jeff Janes, Dean Rasheed)

    Previously, the most common values (MCVs) were identified based on their frequency compared to all column values. Now, MCVs are chosen based on their frequency compared to the non-MCV values. This improves the robustness of the algorithm for both uniform and non-uniform distributions.

  • Improve selectivity estimates for >= and <= (Tom Lane)

    Previously, such cases used the same selectivity estimates as > and <, respectively, unless the comparison constants are MCVs. This change is particularly helpful for queries involving BETWEEN with small ranges.

  • Reduce var = var to var IS NOT NULL where equivalent (Tom Lane)

    This leads to better selectivity estimates.

  • Improve optimizer's row count estimates for EXISTS and NOT EXISTS queries (Tom Lane)

  • Make the optimizer account for evaluation costs and selectivity of HAVING clauses (Tom Lane)

  • Add Just-in-Time (JIT) compilation of some parts of query plans to improve execution speed (Andres Freund)

    This feature requires LLVM to be available. It is not currently enabled by default, even in builds that support it.

  • Allow bitmap scans to perform index-only scans when possible (Alexander Kuzmenkov)

  • Update the free space map during VACUUM (Claudio Freire)

    This allows free space to be reused more quickly.

  • Allow VACUUM to avoid unnecessary index scans (Masahiko Sawada, Alexander Korotkov)

  • Improve performance of committing multiple concurrent transactions (Amit Kapila)

  • Reduce memory usage for queries using set-returning functions in their target lists (Andres Freund)

  • Improve the speed of aggregate computations (Andres Freund)

  • Allow postgres_fdw to push UPDATEs and DELETEs using joins to foreign servers (Etsuro Fujita)

    Previously, only non-join UPDATEs and DELETEs were pushed.

  • Add support for large pages on Windows (Takayuki Tsunakawa, Thomas Munro)

    This is controlled by the huge_pages configuration parameter.

  • Show memory usage in output from log_statement_stats, log_parser_stats, log_planner_stats, and log_executor_stats (Justin Pryzby, Peter Eisentraut)

  • Add column pg_stat_activity.backend_type to show the type of a background worker (Peter Eisentraut)

    The type is also visible in ps output.

  • Make log_autovacuum_min_duration log skipped tables that are concurrently being dropped (Nathan Bossart)

  • Add information_schema columns related to table constraints and triggers (Peter Eisentraut)

    Specifically, triggers.action_order, triggers.action_reference_old_table, and triggers.action_reference_new_table are now populated, where before they were always null. Also, table_constraints.enforced now exists but is not yet usefully populated.

  • Allow the server to specify more complex LDAP specifications in search+bind mode (Thomas Munro)

    Specifically, ldapsearchfilter allows pattern matching using combinations of LDAP attributes.

  • Allow LDAP authentication to use encrypted LDAP (Thomas Munro)

    We already supported LDAP over TLS by using ldaptls=1. This new TLS LDAP method for encrypted LDAP is enabled with ldapscheme=ldaps or ldapurl=ldaps://.

  • Improve logging of LDAP errors (Thomas Munro)

  • Add default roles that enable file system access (Stephen Frost)

    Specifically, the new roles are: pg_read_server_files, pg_write_server_files, and pg_execute_server_program. These roles now also control who can use server-side COPY and the file_fdw extension. Previously, only superusers could use these functions, and that is still the default behavior.

  • Allow access to file system functions to be controlled by GRANT/REVOKE permissions, rather than superuser checks (Stephen Frost)

    Specifically, these functions were modified: pg_ls_dir(), pg_read_file(), pg_read_binary_file(), pg_stat_file().

  • Use GRANT/REVOKE to control access to lo_import() and lo_export() (Michael Paquier, Tom Lane)

    Previously, only superusers were granted access to these functions.

    The compile-time option ALLOW_DANGEROUS_LO_FUNCTIONS has been removed.

  • Use view owner not session owner when preventing non-password access to postgres_fdw tables (Robert Haas)

    PostgreSQL only allows superusers to access postgres_fdw tables without passwords, e.g. via peer. Previously, the session owner had to be a superuser to allow such access; now the view owner is checked instead.

  • Fix invalid locking permission check in SELECT FOR UPDATE on views (Tom Lane)

  • Add server setting ssl_passphrase_command to allow supplying of the passphrase for SSL key files (Peter Eisentraut)

    Also add ssl_passphrase_command_supports_reload to specify whether the SSL configuration should be reloaded and ssl_passphrase_command called during a server configuration reload.

  • Add storage parameter toast_tuple_target to control the minimum tuple length before TOAST storage will be considered (Simon Riggs)

    The default TOAST threshold has not been changed.

  • Allow server options related to memory and file sizes to be specified in units of bytes (Beena Emerson)

    The new unit suffix is “B”. This is in addition to the existing units “kB”, “MB”, “GB” and “TB”.

  • Allow the WAL file size to be set during initdb (Beena Emerson)

    Previously, the 16MB default could only be changed at compile time.

  • Retain WAL data for only a single checkpoint (Simon Riggs)

    Previously, WAL was retained for two checkpoints.

  • Fill the unused portion of force-switched WAL segment files with zeros for improved compressibility (Chapman Flack)

  • Replicate TRUNCATE activity when using logical replication (Simon Riggs, Marco Nenciarini, Peter Eisentraut)

  • Pass prepared transaction information to logical replication subscribers (Nikhil Sontakke, Stas Kelvich)

  • Exclude unlogged tables, temporary tables, and pg_internal.init files from streaming base backups (David Steele)

    There is no need to copy such files.

  • Allow checksums of heap pages to be verified during streaming base backup (Michael Banck)

  • Allow replication slots to be advanced programmatically, rather than be consumed by subscribers (Petr Jelinek)

    This allows efficient advancement of replication slots when the contents do not need to be consumed. This is performed by pg_replication_slot_advance().

  • Add timeline information to the backup_label file (Michael Paquier)

    Also add a check that the WAL timeline matches the backup_label file's timeline.

  • Add host and port connection information to the pg_stat_wal_receiver system view (Haribabu Kommi)

  • Allow ALTER TABLE to add a column with a non-null default without doing a table rewrite (Andrew Dunstan, Serge Rielau)

    This is enabled when the default value is a constant.

  • Allow views to be locked by locking the underlying tables (Yugo Nagata)

  • Allow ALTER INDEX to set statistics-gathering targets for expression indexes (Alexander Korotkov, Adrien Nayrat)

    In psql, \d+ now shows the statistics target for indexes.

  • Allow multiple tables to be specified in one VACUUM or ANALYZE command (Nathan Bossart)

    Also, if any table mentioned in VACUUM uses a column list, then the ANALYZE keyword must be supplied; previously, ANALYZE was implied in such cases.

  • Add parenthesized options syntax to ANALYZE (Nathan Bossart)

    This is similar to the syntax supported by VACUUM.

  • Add CREATE AGGREGATE option to specify the behavior of the aggregate's finalization function (Tom Lane)

    This is helpful for allowing user-defined aggregate functions to be optimized and to work as window functions.

  • Allow the creation of arrays of domains (Tom Lane)

    This also allows array_agg() to be used on domains.

  • Support domains over composite types (Tom Lane)

    Also allow PL/Perl, PL/Python, and PL/Tcl to handle composite-domain function arguments and results. Also improve PL/Python domain handling.

  • Add casts from JSONB scalars to numeric and boolean data types (Anastasia Lubennikova)

  • Add all window function framing options specified by SQL:2011 (Oliver Ford, Tom Lane)

    Specifically, allow RANGE mode to use PRECEDING and FOLLOWING to select rows having grouping values within plus or minus the specified offset. Add GROUPS mode to include plus or minus the number of peer groups. Frame exclusion syntax was also added.

  • Add SHA-2 family of hash functions (Peter Eisentraut)

    Specifically, sha224(), sha256(), sha384(), sha512() were added.

  • Add support for 64-bit non-cryptographic hash functions (Robert Haas, Amul Sul)

  • Allow to_char() and to_timestamp() to specify the time zone's offset from UTC in hours and minutes (Nikita Glukhov, Andrew Dunstan)

    This is done with format specifications TZH and TZM.

  • Add text search function websearch_to_tsquery() that supports a query syntax similar to that used by web search engines (Victor Drobny, Dmitry Ivanov)

  • Add functions json(b)_to_tsvector() to create a text search query for matching JSON/JSONB values (Dmitry Dolgov)

  • Add SQL-level procedures, which can start and commit their own transactions (Peter Eisentraut)

    They are created with the new CREATE PROCEDURE command and invoked via CALL.

    The new ALTER/DROP ROUTINE commands allow altering/dropping of all routine-like objects, including procedures, functions, and aggregates.

    Also, writing FUNCTION is now preferred over writing PROCEDURE in CREATE OPERATOR and CREATE TRIGGER, because the referenced object must be a function not a procedure. However, the old syntax is still accepted for compatibility.

  • Add transaction control to PL/pgSQL, PL/Perl, PL/Python, PL/Tcl, and SPI server-side languages (Peter Eisentraut)

    Transaction control is only available within top-transaction-level procedures and nested DO and CALL blocks that only contain other DO and CALL blocks.

  • Add the ability to define PL/pgSQL composite-type variables as not null, constant, or with initial values (Tom Lane)

  • Allow PL/pgSQL to handle changes to composite types (e.g. record, row) that happen between the first and later function executions in the same session (Tom Lane)

    Previously, such circumstances generated errors.

  • Add extension jsonb_plpython to transform JSONB to/from PL/Python types (Anthony Bykov)

  • Add extension jsonb_plperl to transform JSONB to/from PL/Perl types (Anthony Bykov)

  • Change libpq to disable compression by default (Peter Eisentraut)

    Compression is already disabled in modern OpenSSL versions, so that the libpq setting had no effect with such libraries.

  • Add DO CONTINUE option to ecpg's WHENEVER statement (Vinayak Pokale)

    This generates a C continue statement, causing a return to the top of the contained loop when the specified condition occurs.

  • Add an ecpg mode to enable Oracle Pro*C-style handling of char arrays.

    This mode is enabled with -C.

  • Add psql command \gdesc to display the names and types of the columns in a query result (Pavel Stehule)

  • Add psql variables to report query activity and errors (Fabien Coelho)

    Specifically, the new variables are ERROR, SQLSTATE, ROW_COUNT, LAST_ERROR_MESSAGE, and LAST_ERROR_SQLSTATE.

  • Allow psql to test for the existence of a variable (Fabien Coelho)

    Specifically, the syntax :{?variable_name} allows a variable's existence to be tested in an \if statement.

  • Allow environment variable PSQL_PAGER to control psql's pager (Pavel Stehule)

    This allows psql's default pager to be specified as a separate environment variable from the pager for other applications. PAGER is still honored if PSQL_PAGER is not set.

  • Make psql's \d+ command always show the table's partitioning information (Amit Langote, Ashutosh Bapat)

    Previously, partition information would not be displayed for a partitioned table if it had no partitions. Also indicate which partitions are themselves partitioned.

  • Ensure that psql reports the proper user name when prompting for a password (Tom Lane)

    Previously, combinations of -U and a user name embedded in a URI caused incorrect reporting. Also suppress the user name before the password prompt when --password is specified.

  • Allow quit and exit to exit psql when given with no prior input (Bruce Momjian)

    Also print hints about how to exit when quit and exit are used alone on a line while the input buffer is not empty. Add a similar hint for help.

  • Make psql hint at using control-D when \q is entered alone on a line but ignored (Bruce Momjian)

    For example, \q does not exit when supplied in character strings.

  • Improve tab completion for ALTER INDEX RESET/SET (Masahiko Sawada)

  • Add infrastructure to allow psql to adapt its tab completion queries based on the server version (Tom Lane)

    Previously, tab completion queries could fail against older servers.

  • Add pgbench expression support for NULLs, booleans, and some functions and operators (Fabien Coelho)

  • Add \if conditional support to pgbench (Fabien Coelho)

  • Allow the use of non-ASCII characters in pgbench variable names (Fabien Coelho)

  • Add pgbench option --init-steps to control the initialization steps performed (Masahiko Sawada)

  • Add an approximately Zipfian-distributed random generator to pgbench (Alik Khilazhev)

  • Allow the random seed to be set in pgbench (Fabien Coelho)

  • Allow pgbench to do exponentiation with pow() and power() (Raúl Marín Rodríguez)

  • Add hashing functions to pgbench (Ildar Musin)

  • Make pgbench statistics more accurate when using --latency-limit and --rate (Fabien Coelho)

  • Add an option to pg_basebackup that creates a named replication slot (Michael Banck)

    The option --create-slot creates the named replication slot (--slot) when the WAL streaming method (--wal-method=stream) is used.

  • Allow initdb to set group read access to the data directory (David Steele)

    This is accomplished with the new initdb option --allow-group-access. Administrators can also set group permissions on the empty data directory before running initdb. Server variable data_directory_mode allows reading of data directory group permissions.

  • Add pg_verify_checksums tool to verify database checksums while offline (Magnus Hagander)

  • Allow pg_resetwal to change the WAL segment size via --wal-segsize (Nathan Bossart)

  • Add long options to pg_resetwal and pg_controldata (Nathan Bossart, Peter Eisentraut)

  • Add pg_receivewal option --no-sync to prevent synchronous WAL writes, for testing (Michael Paquier)

  • Add pg_receivewal option --endpos to specify when WAL receiving should stop (Michael Paquier)

  • Allow pg_ctl to send the SIGKILL signal to processes (Andres Freund)

    This was previously unsupported due to concerns over possible misuse.

  • Reduce the number of files copied by pg_rewind (Michael Paquier)

  • Prevent pg_rewind from running as root (Michael Paquier)

  • Add pg_dumpall option --encoding to control output encoding (Michael Paquier)

    pg_dump already had this option.

  • Add pg_dump option --load-via-partition-root to force loading of data into the partition's root table, rather than the original partition (Rushabh Lathia)

    This is useful if the system to be loaded to has different collation definitions or endianness, possibly requiring rows to be stored in different partitions than previously.

  • Add an option to suppress dumping and restoring database object comments (Robins Tharakan)

    The new pg_dump, pg_dumpall, and pg_restore option is --no-comments.

  • Add PGXS support for installing include files (Andrew Gierth)

    This supports creating extension modules that depend on other modules. Formerly there was no easy way for the dependent module to find the referenced one's include files. Several existing contrib modules that define data types have been adjusted to install relevant files. Also, PL/Perl and PL/Python now install their include files, to support creation of transform modules for those languages.

  • Install errcodes.txt to allow extensions to access the list of error codes known to PostgreSQL (Thomas Munro)

  • Convert documentation to DocBook XML (Peter Eisentraut, Alexander Lakhin, Jürgen Purtz)

    The file names still use an sgml extension for compatibility with back branches.

  • Use stdbool.h to define type bool on platforms where it's suitable, which is most (Peter Eisentraut)

    This eliminates a coding hazard for extension modules that need to include stdbool.h.

  • Overhaul the way that initial system catalog contents are defined (John Naylor)

    The initial data is now represented in Perl data structures, making it much easier to manipulate mechanically.

  • Prevent extensions from creating custom server parameters that take a quoted list of values (Tom Lane)

    This cannot be supported at present because knowledge of the parameter's property would be required even before the extension is loaded.

  • Add ability to use channel binding when using SCRAM authentication (Michael Paquier)

    Channel binding is intended to prevent man-in-the-middle attacks, but SCRAM cannot prevent them unless it can be forced to be active. Unfortunately, there is no way to do that in libpq. Support for it is expected in future versions of libpq and in interfaces not built using libpq, e.g. JDBC.

  • Allow background workers to attach to databases that normally disallow connections (Magnus Hagander)

  • Add support for hardware CRC calculations on ARMv8 (Yuqi Gu, Heikki Linnakangas, Thomas Munro)

  • Speed up lookups of built-in functions by OID (Andres Freund)

    The previous binary search has been replaced by a lookup array.

  • Speed up construction of query results (Andres Freund)

  • Improve speed of access to system caches (Andres Freund)

  • Add a generational memory allocator which is optimized for serial allocation/deallocation (Tomas Vondra)

    This reduces memory usage for logical decoding.

  • Make the computation of pg_class.reltuples by VACUUM consistent with its computation by ANALYZE (Tomas Vondra)

  • Update to use perltidy version 20170521 (Tom Lane, Peter Eisentraut)

  • Allow extension pg_prewarm to restore the previous shared buffer contents on startup (Mithun Cy, Robert Haas)

    This is accomplished by having pg_prewarm store the shared buffers' relation and block number data to disk occasionally during server operation, and at shutdown.

  • Add pg_trgm function strict_word_similarity() to compute the similarity of whole words (Alexander Korotkov)

    The function word_similarity() already existed for this purpose, but it was designed to find similar parts of words, while strict_word_similarity() computes the similarity to whole words.

  • Allow btree_gin to index bool, bpchar, name and uuid data types (Matheus Oliveira)

  • Allow cube and seg extensions to perform index-only scans using GiST indexes (Andrey Borodin)

  • Allow retrieval of negative cube coordinates using the ~> operator (Alexander Korotkov)

    This is useful for KNN-GiST searches when looking for coordinates in descending order.

  • Add Vietnamese letter handling to the unaccent extension (Dang Minh Huong, Michael Paquier)

  • Enhance amcheck to check that each heap tuple has an index entry (Peter Geoghegan)

  • Have adminpack use the new default file system access roles (Stephen Frost)

    Previously, only superusers could call adminpack functions; now role permissions are checked.

  • Widen pg_stat_statement's query ID to 64 bits (Robert Haas)

    This greatly reduces the chance of query ID hash collisions. The query ID can now potentially display as a negative value.

  • Remove the contrib/start-scripts/osx scripts since they are no longer recommended (use contrib/start-scripts/macos instead) (Tom Lane)

  • Remove the chkpass extension (Peter Eisentraut)

    This extension is no longer considered to be a usable security tool or example of how to write an extension.

• ⇑ Upgrade to 11.1 released on 2018-11-08 - docs

  • Ensure proper quoting of transition table names when pg_dump emits CREATE TRIGGER ... REFERENCING commands (Tom Lane)

    This oversight could be exploited by an unprivileged user to gain superuser privileges during the next dump/reload or pg_upgrade run. (CVE-2018-16850)

  • Apply the tablespace specified for a partitioned index when creating a child index (Álvaro Herrera)

    Previously, child indexes were always created in the default tablespace.

  • Fix NULL handling in parallel hashed multi-batch left joins (Andrew Gierth, Thomas Munro)

    Outer-relation rows with null values of the hash key were omitted from the join result.

  • Fix incorrect processing of an array-type coercion expression appearing within a CASE clause that has a constant test expression (Tom Lane)

  • Fix incorrect expansion of tuples lacking recently-added columns (Andrew Dunstan, Amit Langote)

    This is known to lead to crashes in triggers on tables with recently-added columns, and could have other symptoms as well.

  • Fix bugs with named or defaulted arguments in CALL argument lists (Tom Lane, Pavel Stehule)

  • Fix strictness check for strict aggregates with ORDER BY columns (Andrew Gierth, Andres Freund)

    The strictness logic incorrectly ignored rows for which the ORDER BY value(s) were null.

  • Disable recheck_on_update optimization (Tom Lane)

    This new-in-v11 feature turns out not to have been ready for prime time. Disable it until something can be done about it.

  • Prevent creation of a partition in a trigger attached to its parent table (Amit Langote)

    Ideally we'd allow that, but for the moment it has to be blocked to avoid crashes.

  • Fix problems with applying ON COMMIT DELETE ROWS to a partitioned temporary table (Amit Langote)

  • Fix character-class checks to not fail on Windows for Unicode characters above U+FFFF (Tom Lane, Kenji Uno)

    This bug affected full-text-search operations, as well as contrib/ltree and contrib/pg_trgm.

  • Ensure that the server will process already-received NOTIFY and SIGTERM interrupts before waiting for client input (Jeff Janes, Tom Lane)

  • Fix memory leak in repeated SP-GiST index scans (Tom Lane)

    This is only known to amount to anything significant in cases where an exclusion constraint using SP-GiST receives many new index entries in a single command.

  • Prevent starting the server with wal_level set to too low a value to support an existing replication slot (Andres Freund)

  • Fix psql, as well as documentation examples, to call PQconsumeInput() before each PQnotifies() call (Tom Lane)

    This fixes cases in which psql would not report receipt of a NOTIFY message until after the next command.

  • Fix pg_verify_checksums's determination of which files to check the checksums of (Michael Paquier)

    In some cases it complained about files that are not expected to have checksums.

  • In contrib/pg_stat_statements, disallow the pg_read_all_stats role from executing pg_stat_statements_reset() (Haribabu Kommi)

    pg_read_all_stats is only meant to grant permission to read statistics, not to change them, so this grant was incorrect.

    To cause this change to take effect, run ALTER EXTENSION pg_stat_statements UPDATE in each database where pg_stat_statements has been installed. (A database freshly created in 11.0 should not need this, but a database upgraded from a previous release probably still contains the old version of pg_stat_statements. The UPDATE command is harmless if the module was already updated.)

  • Rename red-black tree support functions to use rbt prefix not rb prefix (Tom Lane)

    This avoids name collisions with Ruby functions, which broke PL/Ruby. It's hoped that there are no other affected extensions.

  • Fix build problems on macOS 10.14 (Mojave) (Tom Lane)

    Adjust configure to add an -isysroot switch to CPPFLAGS; without this, PL/Perl and PL/Tcl fail to configure or build on macOS 10.14. The specific sysroot used can be overridden at configure time or build time by setting the PG_SYSROOT variable in the arguments of configure or make.

    It is now recommended that Perl-related extensions write $(perl_includespec) rather than -I$(perl_archlibexp)/CORE in their compiler flags. The latter continues to work on most platforms, but not recent macOS.

    Also, it should no longer be necessary to specify --with-tclconfig manually to get PL/Tcl to build on recent macOS releases.

  • Fix MSVC build and regression-test scripts to work on recent Perl versions (Andrew Dunstan)

    Perl no longer includes the current directory in its search path by default; work around that.

  • On Windows, allow the regression tests to be run by an Administrator account (Andrew Dunstan)

    To do this safely, pg_regress now gives up any such privileges at startup.

  • Update time zone data files to tzdata release 2018g for DST law changes in Chile, Fiji, Morocco, and Russia (Volgograd), plus historical corrections for China, Hawaii, Japan, Macau, and North Korea.

• ⇑ Upgrade to 11.2 released on 2019-02-14 - docs

  • By default, panic instead of retrying after fsync() failure, to avoid possible data corruption (Craig Ringer, Thomas Munro)

    Some popular operating systems discard kernel data buffers when unable to write them out, reporting this as fsync() failure. If we reissue the fsync() request it will succeed, but in fact the data has been lost, so continuing risks database corruption. By raising a panic condition instead, we can replay from WAL, which may contain the only remaining copy of the data in such a situation. While this is surely ugly and inefficient, there are few alternatives, and fortunately the case happens very rarely.

    A new server parameter data_sync_retry has been added to control this; if you are certain that your kernel does not discard dirty data buffers in such scenarios, you can set data_sync_retry to on to restore the old behavior.

  • Include each major release branch's release notes in the documentation for only that branch, rather than that branch and all later ones (Tom Lane)

    The duplication induced by the previous policy was getting out of hand. Our plan is to provide a full archive of release notes on the project's web site, but not duplicate it within each release.

  • Fix handling of unique indexes with INCLUDE columns on partitioned tables (Álvaro Herrera)

    The uniqueness condition was not checked properly in such cases.

  • Ensure that NOT NULL constraints of a partitioned table are honored within its partitions (Álvaro Herrera, Amit Langote)

  • Update catalog state correctly for partition table constraints when detaching their partition (Amit Langote, Álvaro Herrera)

    Previously, the pg_constraint.conislocal field for such a constraint might improperly be left as false, rendering it undroppable. A dump/restore or pg_upgrade would cure the problem, but if necessary, the catalog field can be adjusted manually.

  • Create or delete foreign key enforcement triggers correctly when attaching or detaching a partition in a partitioned table that has a foreign-key constraint (Amit Langote, Álvaro Herrera)

  • Avoid useless creation of duplicate foreign key constraints in partitioned tables (Álvaro Herrera)

  • When an index is created on a partitioned table using ONLY, and there are no partitions yet, mark it valid immediately (Álvaro Herrera)

    Otherwise there is no way to make it become valid.

  • Use a safe table lock level when detaching a partition (Álvaro Herrera)

    The previous locking level was too weak and might allow concurrent DDL on the table, with bad results.

  • Fix problems with applying ON COMMIT DROP and ON COMMIT DELETE ROWS to partitioned tables and tables with inheritance children (Michael Paquier)

  • Disallow COPY FREEZE on partitioned tables (David Rowley)

    This should eventually be made to work, but it may require a patch that's too complicated to risk back-patching.

  • Fix possible index corruption when the indexed column has a “fast default” (that is, it was added by ALTER TABLE ADD COLUMN with a constant non-NULL default value specified, after the table already contained some rows) (Andres Freund)

  • Correctly adjust “fast default” values during ALTER TABLE ... ALTER COLUMN TYPE (Andrew Dunstan)

  • Avoid possible deadlock when acquiring multiple buffer locks (Nishant Fnu)

  • Avoid deadlock between GIN vacuuming and concurrent index insertions (Alexander Korotkov, Andrey Borodin, Peter Geoghegan)

    This change partially reverts a performance improvement, introduced in version 10.0, that attempted to reduce the number of index pages locked during deletion of a GIN posting tree page. That's now been found to lead to deadlocks, so we've removed it pending closer analysis.

  • Avoid deadlock between hot-standby queries and replay of GIN index page deletion (Alexander Korotkov)

  • Fix possible crashes in logical replication when index expressions or predicates are in use (Peter Eisentraut)

  • Avoid useless and expensive logical decoding of TOAST data during a table rewrite (Tomas Vondra)

  • Fix logic for stopping a subset of WAL senders when synchronous replication is enabled (Paul Guo, Michael Paquier)

  • Avoid possibly writing an incorrect replica identity field in a tuple deletion WAL record (Stas Kelvich)

  • Prevent incorrect use of WAL-skipping optimization during COPY to a view or foreign table (Amit Langote, Michael Paquier)

  • Make the archiver prioritize WAL history files over WAL data files while choosing which file to archive next (David Steele)

  • Fix possible crash in UPDATE with a multiple SET clause using a sub-SELECT as source (Tom Lane)

  • Fix crash when zero rows are fed to json[b]_populate_recordset() or json[b]_to_recordset() (Tom Lane)

  • Avoid crash if libxml2 returns a null error message (Sergio Conde Gómez)

  • Fix incorrect JIT tuple deforming code for tables with many columns (more than approximately 800) (Andres Freund)

  • Fix performance and memory leakage issues in hash-based grouping (Andres Freund)

  • Fix spurious grouping-related parser errors caused by inconsistent handling of collation assignment (Andrew Gierth)

    In some cases, expressions that should be considered to match were not seen as matching, if they included operations on collatable data types.

  • Fix parsing of collation-sensitive expressions in the arguments of a CALL statement (Peter Eisentraut)

  • Ensure proper cleanup after detecting an error in the argument list of a CALL statement (Tom Lane)

  • Check whether the comparison function underlying LEAST() or GREATEST() is leakproof, rather than just assuming it is (Tom Lane)

    Actual information leaks from btree comparison functions are typically hard to provoke, but in principle they could happen.

  • Fix incorrect planning of queries involving nested loops both above and below a Gather plan node (Tom Lane)

    If both levels of nestloop needed to pass the same variable into their right-hand sides, an incorrect plan would be generated.

  • Fix incorrect planning of queries in which a lateral reference must be evaluated at a foreign table scan (Tom Lane)

  • Fix planner failure when the first column of a row comparison matches an index column, but later column(s) do not, and the index has included (non-key) columns (Tom Lane)

  • Fix corner-case underestimation of the cost of a merge join (Tom Lane)

    The planner could prefer a merge join when the outer key range is much smaller than the inner key range, even if there are so many duplicate keys on the inner side that this is a poor choice.

  • Avoid O(N^2) planning time growth when a query contains many thousand indexable clauses (Tom Lane)

  • Improve planning speed for large inheritance or partitioning table groups (Amit Langote, Etsuro Fujita)

  • Improve ANALYZE's handling of concurrently-updated rows (Jeff Janes, Tom Lane)

    Previously, rows deleted by an in-progress transaction were omitted from ANALYZE's sample, but this has been found to lead to more inconsistency than including them would do. In effect, the sample now corresponds to an MVCC snapshot as of ANALYZE's start time.

  • Make TRUNCATE ignore inheritance child tables that are temporary tables of other sessions (Amit Langote, Michael Paquier)

    This brings TRUNCATE into line with the behavior of other commands. Previously, such cases usually ended in failure.

  • Fix TRUNCATE to update the statistics counters for the right table (Tom Lane)

    If the truncated table had a TOAST table, that table's counters were reset instead.

  • Process ALTER TABLE ONLY ADD COLUMN IF NOT EXISTS correctly (Greg Stark)

  • Allow UNLISTEN in hot-standby mode (Shay Rojansky)

    This is necessarily a no-op, because LISTEN isn't allowed in hot-standby mode; but allowing the dummy operation simplifies session-state-reset logic in clients.

  • Fix missing role dependencies in some schema and data type permissions lists (Tom Lane)

    In some cases it was possible to drop a role to which permissions had been granted. This caused no immediate problem, but a subsequent dump/reload or upgrade would fail, with symptoms involving attempts to grant privileges to all-numeric role names.

  • Prevent use of a session's temporary schema within a two-phase transaction (Michael Paquier)

    Accessing a temporary table within such a transaction has been forbidden for a long time, but it was still possible to cause problems with other operations on temporary objects.

  • Ensure relation caches are updated properly after adding or removing foreign key constraints (Álvaro Herrera)

    This oversight could result in existing sessions failing to enforce a newly-created constraint, or continuing to enforce a dropped one.

  • Ensure relation caches are updated properly after renaming constraints (Amit Langote)

  • Fix replay of GiST index micro-vacuum operations so that concurrent hot-standby queries do not see inconsistent state (Alexander Korotkov)

  • Prevent empty GIN index pages from being reclaimed too quickly, causing failures of concurrent searches (Andrey Borodin, Alexander Korotkov)

  • Fix edge-case failures in float-to-integer coercions (Andrew Gierth, Tom Lane)

    Values very slightly above the maximum valid integer value might not be rejected, and then would overflow, producing the minimum valid integer instead. Also, values that should round to the minimum or maximum integer value might be incorrectly rejected.

  • Fix parsing of space-separated lists of host names in the ldapserver parameter of LDAP authentication entries in pg_hba.conf (Thomas Munro)

  • When making a PAM authentication request, don't set the PAM_RHOST variable if the connection is via a Unix socket (Thomas Munro)

    Previously that variable would be set to [local], which is at best unhelpful, since it's supposed to be a host name.

  • Disallow setting client_min_messages higher than ERROR (Jonah Harris, Tom Lane)

    Previously, it was possible to set this variable to FATAL or PANIC, which had the effect of suppressing transmission of ordinary error messages to the client. However, that's contrary to guarantees that are given in the PostgreSQL wire protocol specification, and it caused some clients to become very confused. In released branches, fix this by silently treating such settings as meaning ERROR instead. Version 12 and later will reject those alternatives altogether.

  • Fix ecpglib to use uselocale() or _configthreadlocale() in preference to setlocale() (Michael Meskes, Tom Lane)

    Since setlocale() is not thread-local, and might not even be thread-safe, the previous coding caused problems in multi-threaded ecpg applications.

  • Fix incorrect results for numeric data passed through an ecpg SQLDA (SQL Descriptor Area) (Daisuke Higuchi)

    Values with leading zeroes were not copied correctly.

  • Fix psql's \g target meta-command to work with COPY TO STDOUT (Daniel Vérité)

    Previously, the target option was ignored, so that the copy data always went to the current query output target.

  • Make psql's LaTeX output formats render special characters properly (Tom Lane)

    Backslash and some other ASCII punctuation characters were not rendered correctly, leading to document syntax errors or wrong characters in the output.

  • Make pgbench's random number generation fully deterministic and platform-independent when --random-seed=N is specified (Fabien Coelho, Tom Lane)

    On any specific platform, the sequence obtained with a particular value of N will probably be different from what it was before this patch.

  • Fix pg_basebackup and pg_verify_checksums to ignore temporary files appropriately (Michael Banck, Michael Paquier)

  • Fix pg_dump's handling of materialized views with indirect dependencies on primary keys (Tom Lane)

    This led to mis-labeling of such views' dump archive entries, causing harmless warnings about “archive items not in correct section order”; less harmlessly, selective-restore options depending on those labels, such as --section, might misbehave.

  • Make pg_dump include ALTER INDEX SET STATISTICS commands (Michael Paquier)

    When the ability to attach statistics targets to index expressions was added, we forgot to teach pg_dump about it, so that such settings were lost in dump/reload.

  • Fix pg_dump's dumping of tables that have OIDs (Peter Eisentraut)

    The WITH OIDS clause was omitted if it needed to be applied to the first table to be dumped.

  • Avoid null-pointer-dereference crash on some platforms when pg_dump or pg_restore tries to report an error (Tom Lane)

  • Prevent false index-corruption reports from contrib/amcheck caused by inline-compressed data (Peter Geoghegan)

  • Properly disregard SIGPIPE errors if COPY FROM PROGRAM stops reading the program's output early (Tom Lane)

    This case isn't actually reachable directly with COPY, but it can happen when using contrib/file_fdw.

  • Fix contrib/hstore to calculate correct hash values for empty hstore values that were created in version 8.4 or before (Andrew Gierth)

    The previous coding did not give the same result as for an empty hstore value created by a newer version, thus potentially causing wrong results in hash joins or hash aggregation. It is advisable to reindex any hash indexes built on hstore columns, if the table might contain data that was originally stored as far back as 8.4 and was never dumped/reloaded since then.

  • Avoid crashes and excessive runtime with large inputs to contrib/intarray's gist__int_ops index support (Andrew Gierth)

  • In configure, look for python3 and then python2 if python isn't found (Peter Eisentraut)

    This allows PL/Python to be configured without explicitly specifying PYTHON on platforms that no longer provide an unversioned python executable.

  • Include JIT-related headers in the installed set of header files (Donald Dong)

  • Support new Makefile variables PG_CFLAGS, PG_CXXFLAGS, and PG_LDFLAGS in pgxs builds (Christoph Berg)

    This simplifies customization of extension build processes.

  • Fix Perl-coded build scripts to not assume “.” is in the search path, since recent Perl versions don't include that (Andrew Dunstan)

  • Fix server command-line option parsing problems on OpenBSD (Tom Lane)

  • Relocate call of set_rel_pathlist_hook so that extensions can use it to supply partial paths for parallel queries (KaiGai Kohei)

    This is not expected to affect existing use-cases.

  • Update time zone data files to tzdata release 2018i for DST law changes in Kazakhstan, Metlakatla, and Sao Tome and Principe. Kazakhstan's Qyzylorda zone is split in two, creating a new zone Asia/Qostanay, as some areas did not change UTC offset. Historical corrections for Hong Kong and numerous Pacific islands.

• ⇑ Upgrade to 11.3 released on 2019-05-09 - docs

  • Prevent row-level security policies from being bypassed via selectivity estimators (Dean Rasheed)

    Some of the planner's selectivity estimators apply user-defined operators to values found in pg_statistic (e.g., most-common values). A leaky operator therefore can disclose some of the entries in a data column, even if the calling user lacks permission to read that column. In CVE-2017-7484 we added restrictions to forestall that, but we failed to consider the effects of row-level security. A user who has SQL permission to read a column, but who is forbidden to see certain rows due to RLS policy, might still learn something about those rows' contents via a leaky operator. This patch further tightens the rules, allowing leaky operators to be applied to statistics data only when there is no relevant RLS policy. (CVE-2019-10130)

  • Avoid access to already-freed memory during partition routing error reports (Michael Paquier)

    This mistake could lead to a crash, and in principle it might be possible to use it to disclose server memory contents. (CVE-2019-10129)

  • Avoid catalog corruption when an ALTER TABLE on a partitioned table finds that a partitioned index is reusable (Amit Langote, Tom Lane)

    This occurs, for example, when ALTER COLUMN TYPE finds that no physical table rewrite is required.

  • Avoid catalog corruption when a temporary table with ON COMMIT DROP and an identity column is created in a single-statement transaction (Peter Eisentraut)

    This hazard was overlooked because the case is not actually useful, since the temporary table would be dropped immediately after creation.

  • Fix failure in ALTER INDEX ... ATTACH PARTITION if the partitioned table contains more dropped columns than its partition does (Álvaro Herrera)

  • Fix failure to attach a partition's existing index to a newly-created partitioned index in some cases (Amit Langote, Álvaro Herrera)

    This would lead to errors such as “index ... not found in partition” in subsequent DDL that uses the partitioned index.

  • Avoid crash when an EPQ recheck is performed for a partitioned query result relation (Amit Langote)

    This occurs when using READ COMMITTED isolation level and another session has concurrently updated some of the target row(s).

  • Fix tuple routing in multi-level partitioned tables that have dropped attributes (Amit Langote, Michael Paquier)

  • Fix failure when the slow path of foreign key constraint initial validation is applied to partitioned tables (Hadi Moshayedi, Tom Lane, Andres Freund)

    This didn't manifest except in the uncommon cases where the fast path can't be used (such as permissions problems).

  • Fix behavior for an UPDATE or DELETE on an inheritance tree or partitioned table in which every table can be excluded (Amit Langote, Tom Lane)

    In such cases, the query did not report the correct set of output columns when a RETURNING clause was present, and if there were any statement-level triggers that should be fired, it didn't fire them.

  • When accessing a partition directly, and constraint_exclusion is set to on, use the partition's partition constraint as well as any CHECK constraints for exclusion checking (Amit Langote, Tom Lane)

    This change restores the behavior to what it was in v10.

  • Avoid server crash when an error occurs while trying to persist a cursor query across a transaction commit (Tom Lane)

    If a procedure attempts to commit while it has an open explicit or implicit cursor (for example, a PL/pgSQL FOR-loop query), the cursor must be executed to completion and its results saved before the transaction commit can be performed. An error occurring during such execution led to a crash.

  • Avoid throwing incorrect errors for updates of temporary tables and unlogged tables when a FOR ALL TABLES publication exists (Peter Eisentraut)

    Such tables should be ignored for publication purposes, but some parts of the code failed to do so.

  • Fix handling of explicit DEFAULT items in an INSERT ... VALUES command with multiple VALUES rows, if the target relation is an updatable view (Amit Langote, Dean Rasheed)

    When the updatable view has no default for the column but its underlying table has one, a single-row INSERT ... VALUES will use the underlying table's default. In the multi-row case, however, NULL was always used. Correct it to act like the single-row case.

  • Fix CREATE VIEW to allow zero-column views (Ashutosh Sharma)

    We should allow this for consistency with allowing zero-column tables. Since a table can be converted to a view, zero-column views could be created even with the restriction in place, leading to dump/reload failures.

  • Add missing support for CREATE TABLE IF NOT EXISTS ... AS EXECUTE ... (Andreas Karlsson)

    The combination of IF NOT EXISTS and EXECUTE should work, but the grammar omitted it.

  • Ensure that sub-SELECTs appearing in row-level-security policy expressions are executed with the correct user's permissions (Dean Rasheed)

    Previously, if the table having the RLS policy was accessed via a view, such checks might be executed as the user calling the view, not as the view owner as they should be.

  • Accept XML documents as valid values of type xml when xmloption is set to content, as required by SQL:2006 and later (Chapman Flack)

    Previously PostgreSQL followed the SQL:2003 definition, which doesn't allow this. But that creates a serious problem for dump/restore: there is no setting of xmloption that will accept all valid XML data. Hence, switch to the 2006 definition.

    pg_dump is also modified to emit SET xmloption = content while restoring data, ensuring that dump/restore works even if the prevailing setting is document.

  • Improve server's startup-time checks for whether a pre-existing shared memory segment is still in use (Noah Misch)

    The postmaster is now more likely to detect that there are still active processes from a previous postmaster incarnation, even if the postmaster.pid file has been removed.

  • Avoid possible division-by-zero in btree index vacuum logic (Piotr Stefaniak, Alexander Korotkov)

    This could lead to incorrect decisions about whether index cleanup is needed.

  • Avoid counting parallel workers' transactions as separate transactions (Haribabu Kommi)

  • Fix incompatibility of GIN-index WAL records (Alexander Korotkov)

    A fix applied in February's minor releases was not sufficiently careful about backwards compatibility, leading to problems if a standby server of that vintage reads GIN page-deletion WAL records generated by a primary server of a previous minor release.

  • Fix possible crash while executing a SHOW command in a replication connection (Michael Paquier)

  • Avoid server memory leak when fetching rows from a portal one at a time (Tom Lane)

  • Avoid memory leak when a partition's relation cache entry is rebuilt (Amit Langote, Tom Lane)

  • Tolerate EINVAL and ENOSYS error results, where appropriate, for fsync and sync_file_range calls (Thomas Munro, James Sewell)

    The previous change to panic on file synchronization failures turns out to have been excessively paranoid for certain cases where a failure is predictable and essentially means “operation not supported”.

  • Report correct relation name in autovacuum's pg_stat_activity display during BRIN summarize operations (Álvaro Herrera)

  • Avoid crash when trying to plan a partition-wise join when GEQO is active (Tom Lane)

  • Fix “failed to build any N-way joins” planner failures with lateral references leading out of FULL outer joins (Tom Lane)

  • Fix misplanning of queries in which a set-returning function is applied to a relation that is provably empty (Tom Lane, Julien Rouhaud)

    In v10, this oversight only led to slightly inefficient plans, but in v11 it could cause “set-valued function called in context that cannot accept a set” errors.

  • Check the appropriate user's permissions when enforcing rules about letting a leaky operator see pg_statistic data (Dean Rasheed)

    When an underlying table is being accessed via a view, consider the privileges of the view owner while deciding whether leaky operators may be applied to the table's statistics data, rather than the privileges of the user making the query. This makes the planner's rules about what data is visible match up with the executor's, avoiding unnecessarily-poor plans.

  • Fix planner's parallel-safety assessment for grouped queries (Etsuro Fujita)

    Previously, target-list evaluation work that could have been parallelized might not be.

  • Fix mishandling of “included” index columns in planner's unique-index logic (Tom Lane)

    This could result in failing to recognize that a unique index with included columns proves uniqueness of a query result, leading to a poor plan.

  • Fix incorrect strictness check for array coercion expressions (Tom Lane)

    This might allow, for example, incorrect inlining of a strict SQL function, leading to non-enforcement of the strictness condition.

  • Speed up planning when there are many equality conditions and many potentially-relevant foreign key constraints (David Rowley)

  • Avoid O(N^2) performance issue when rolling back a transaction that created many tables (Tomas Vondra)

  • Fix corner-case server crashes in dynamic shared memory allocation (Thomas Munro, Robert Haas)

  • Fix race conditions in management of dynamic shared memory (Thomas Munro)

    These could lead to “dsa_area could not attach to segment” or “cannot unpin a segment that is not pinned” errors.

  • Fix race condition in which a hot-standby postmaster could fail to shut down after receiving a smart-shutdown request (Tom Lane)

  • Fix possible crash when pg_identify_object_as_address() is given invalid input (Álvaro Herrera)

  • Fix possible “could not access status of transaction” failures in txid_status() (Thomas Munro)

  • Fix authentication failure when attempting to use SCRAM authentication with mixed OpenSSL library versions (Michael Paquier, Peter Eisentraut)

    If libpq is using OpenSSL 1.0.1 or older while the server is using OpenSSL 1.0.2 or newer, the negotiation of which SASL mechanism to use went wrong, leading to a confusing “channel binding not supported by this build” error message.

  • Tighten validation of encoded SCRAM-SHA-256 and MD5 passwords (Jonathan Katz)

    A password string that had the right initial characters could be mistaken for one that is correctly hashed into SCRAM-SHA-256 or MD5 format. The password would be accepted but would be unusable later.

  • Fix handling of lc_time settings that imply an encoding different from the database's encoding (Juan José Santamaría Flecha, Tom Lane)

    Localized month or day names that include non-ASCII characters previously caused unexpected errors or wrong output in such locales.

  • Create the current_logfiles file with the same permissions as other files in the server's data directory (Haribabu Kommi)

    Previously it used the permissions specified by log_file_mode, but that can cause problems for backup utilities.

  • Fix incorrect operator_precedence_warning checks involving unary minus operators (Rikard Falkeborn)

  • Disallow NaN as a value for floating-point server parameters (Tom Lane)

  • Rearrange REINDEX processing to avoid assertion failures when reindexing individual indexes of pg_class (Andres Freund, Tom Lane)

  • Fix planner assertion failure for parameterized dummy paths (Tom Lane)

  • Insert correct test function in the result of SnapBuildInitialSnapshot() (Antonin Houska)

    No core code cares about this, but some extensions do.

  • Fix intermittent “could not reattach to shared memory” session startup failures on Windows (Noah Misch)

    A previously unrecognized source of these failures is creation of thread stacks for a process's default thread pool. Arrange for such stacks to be allocated in a different memory region.

  • Fix error detection in directory scanning on Windows (Konstantin Knizhnik)

    Errors, such as lack of permissions to read the directory, were not detected or reported correctly; instead the code silently acted as though the directory were empty.

  • Fix grammar problems in ecpg (Tom Lane)

    A missing semicolon led to mistranslation of SET variable = DEFAULT (but not SET variable TO DEFAULT) in ecpg programs, producing syntactically invalid output that the server would reject. Additionally, in a DROP TYPE or DROP DOMAIN command that listed multiple type names, only the first type name was actually processed.

  • Sync ecpg's syntax for CREATE TABLE AS with the server's (Daisuke Higuchi)

  • Fix possible buffer overruns in ecpg's processing of include filenames (Liu Huailing, Fei Wu)

  • Fix pg_rewind failures due to failure to remove some transient files in the target data directory (Michael Paquier)

  • Make pg_verify_checksums verify that the data directory it's pointed at is of the right PostgreSQL version (Michael Paquier)

  • Avoid crash in contrib/postgres_fdw when a query using remote grouping or aggregation has a SELECT-list item that is an uncorrelated sub-select, outer reference, or parameter symbol (Tom Lane)

  • Change contrib/postgres_fdw to report an error when a remote partition chosen to insert a routed row into is also an UPDATE subplan target that will be updated later in the same command (Amit Langote, Etsuro Fujita)

    Previously, such situations led to server crashes or incorrect results of the UPDATE. Allowing such cases to work correctly is a matter for future work.

  • In contrib/pg_prewarm, avoid indefinitely respawning background worker processes if prewarming fails for some reason (Mithun Cy)

  • Avoid crash in contrib/vacuumlo if an lo_unlink() call failed (Tom Lane)

  • Sync our copy of the timezone library with IANA tzcode release 2019a (Tom Lane)

    This corrects a small bug in zic that caused it to output an incorrect year-2440 transition in the Africa/Casablanca zone, and adds support for zic's new -r option.

  • Update time zone data files to tzdata release 2019a for DST law changes in Palestine and Metlakatla, plus historical corrections for Israel.

    Etc/UCT is now a backward-compatibility link to Etc/UTC, instead of being a separate zone that generates the abbreviation UCT, which nowadays is typically a typo. PostgreSQL will still accept UCT as an input zone abbreviation, but it won't output it.

• ⇑ Upgrade to 11.4 released on 2019-06-20 - docs

  • Fix buffer-overflow hazards in SCRAM verifier parsing (Jonathan Katz, Heikki Linnakangas, Michael Paquier)

    Any authenticated user could cause a stack-based buffer overflow by changing their own password to a purpose-crafted value. In addition to the ability to crash the PostgreSQL server, this could suffice for executing arbitrary code as the PostgreSQL operating system account.

    A similar overflow hazard existed in libpq, which could allow a rogue server to crash a client or perhaps execute arbitrary code as the client's operating system account.

    The PostgreSQL Project thanks Alexander Lakhin for reporting this problem. (CVE-2019-10164)

  • Fix assorted errors in run-time partition pruning logic (Tom Lane, Amit Langote, David Rowley)

    These mistakes could lead to wrong answers in queries on partitioned tables, if the comparison value used for pruning is dynamically determined, or if multiple range-partitioned columns are involved in pruning decisions, or if stable (not immutable) comparison operators are involved.

  • Fix possible crash while trying to copy trigger definitions to a new partition (Tom Lane)

  • Fix failure of ALTER TABLE ... ALTER COLUMN TYPE when the table has a partial exclusion constraint (Tom Lane)

  • Fix failure of COMMENT command for comments on domain constraints (Daniel Gustafsson, Michael Paquier)

  • Prevent possible memory clobber when there are duplicate columns in a hash aggregate's hash key list (Andrew Gierth)

  • Fix incorrect argument null-ness checking during partial aggregation of aggregates with zero or multiple arguments (David Rowley, Kyotaro Horiguchi, Andres Freund)

  • Fix faulty generation of merge-append plans (Tom Lane)

    This mistake could lead to “could not find pathkey item to sort” errors.

  • Fix incorrect printing of queries with duplicate join names (Philip Dubé)

    This oversight caused a dump/restore failure for views containing such queries.

  • Fix conversion of JSON string literals to JSON-type output columns in json_to_record() and json_populate_record() (Tom Lane)

    Such cases should produce the literal as a standalone JSON value, but the code misbehaved if the literal contained any characters requiring escaping.

  • Fix misoptimization of {1,1} quantifiers in regular expressions (Tom Lane)

    Such quantifiers were treated as no-ops and optimized away; but the documentation specifies that they impose greediness, or non-greediness in the case of the non-greedy variant {1,1}?, on the subexpression they're attached to, and this did not happen. The misbehavior occurred only if the subexpression contained capturing parentheses or a back-reference.

  • Avoid writing an invalid empty btree index page in the unlikely case that a failure occurs while processing INCLUDEd columns during a page split (Peter Geoghegan)

    The invalid page would not affect normal index operations, but it might cause failures in subsequent VACUUMs. If that has happened to one of your indexes, recover by reindexing the index.

  • Avoid possible failures while initializing a new process's pg_stat_activity data (Tom Lane)

    Certain operations that could fail, such as converting strings extracted from an SSL certificate into the database encoding, were being performed inside a critical section. Failure there would result in database-wide lockup due to violating the access protocol for shared pg_stat_activity data.

  • Fix race condition in check to see whether a pre-existing shared memory segment is still in use by a conflicting postmaster (Tom Lane)

  • Fix unsafe coding in walreceiver's signal handler (Tom Lane)

    This avoids rare problems in which the walreceiver process would crash or deadlock when commanded to shut down.

  • Avoid attempting to do database accesses for parameter checking in processes that are not connected to a specific database (Vignesh C, Andres Freund)

    This error could result in failures like “cannot read pg_class without having selected a database”.

  • Avoid possible hang in libpq if using SSL and OpenSSL's pending-data buffer contains an exact multiple of 256 bytes (David Binderman)

  • Improve initdb's handling of multiple equivalent names for the system time zone (Tom Lane, Andrew Gierth)

    Make initdb examine the /etc/localtime symbolic link, if that exists, to break ties between equivalent names for the system time zone. This makes initdb more likely to select the time zone name that the user would expect when multiple identical time zones exist. It will not change the behavior if /etc/localtime is not a symlink to a zone data file, nor if the time zone is determined from the TZ environment variable.

    Separately, prefer UTC over other spellings of that time zone, when neither TZ nor /etc/localtime provide a hint. This fixes an annoyance introduced by tzdata 2019a's change to make the UCT and UTC zone names equivalent: initdb was then preferring UCT, which almost nobody wants.

  • Fix ordering of GRANT commands emitted by pg_dump and pg_dumpall for databases and tablespaces (Nathan Bossart, Michael Paquier)

    If cascading grants had been issued, restore might fail due to the GRANT commands being given in an order that didn't respect their interdependencies.

  • Make pg_dump recreate table partitions using CREATE TABLE then ATTACH PARTITION, rather than including PARTITION OF in the creation command (Álvaro Herrera, David Rowley)

    This avoids problems with the partition's column order possibly being changed to match the parent's. Also, a partition is now restorable from the dump (as a standalone table) even if its parent table isn't restored; the ATTACH will fail, but that can just be ignored.

  • Fix misleading error reports from reindexdb (Julien Rouhaud)

  • Ensure that vacuumdb returns correct status if an error occurs while using parallel jobs (Julien Rouhaud)

  • Fix contrib/auto_explain to not cause problems in parallel queries (Tom Lane)

    Previously, a parallel worker might try to log its query even if the parent query were not being logged by auto_explain. This would work sometimes, but it's confusing, and in some cases it resulted in failures like “could not find key N in shm TOC”.

    Also, fix an off-by-one error that resulted in not necessarily logging every query even when the sampling rate is set to 1.0.

  • In contrib/postgres_fdw, account for possible data modifications by local BEFORE ROW UPDATE triggers (Shohei Mochizuki)

    If a trigger modified a column that was otherwise not changed by the UPDATE, the new value was not transmitted to the remote server.

  • On Windows, avoid failure when the database encoding is set to SQL_ASCII and we attempt to log a non-ASCII string (Noah Misch)

    The code had been assuming that such strings must be in UTF-8, and would throw an error if they didn't appear to be validly encoded. Now, just transmit the untranslated bytes to the log.

  • Make PL/pgSQL's header files C++-safe (George Tarasov)

• ⇑ Upgrade to 11.5 released on 2019-08-08 - docs

  • Require schema qualification to cast to a temporary type when using functional cast syntax (Noah Misch)

    We have long required invocations of temporary functions to explicitly specify the temporary schema, that is pg_temp.func_name(args). Require this as well for casting to temporary types using functional notation, for example pg_temp.type_name(arg). Otherwise it's possible to capture a function call using a temporary object, allowing privilege escalation in much the same ways that we blocked in CVE-2007-2138. (CVE-2019-10208)

  • Fix execution of hashed subplans that require cross-type comparison (Tom Lane, Andreas Seltenreich)

    Hashed subplans used the outer query's original comparison operator to compare entries of the hash table. This is the wrong thing if that operator is cross-type, since all the hash table entries will be of the subquery's output type. For the set of hashable cross-type operators in core PostgreSQL, this mistake seems nearly harmless on 64-bit machines, but it can result in crashes or perhaps unauthorized disclosure of server memory on 32-bit machines. Extensions might provide hashable cross-type operators that create larger risks. (CVE-2019-10209)

  • Fix failure of ALTER TABLE ... ALTER COLUMN TYPE when altering multiple columns' types in one command (Tom Lane)

    This fixes a regression introduced in the most recent minor releases: indexes using the altered columns were not processed correctly, leading to strange failures during ALTER TABLE.

  • Prevent dropping a partitioned table's trigger if there are pending trigger events in child partitions (Álvaro Herrera)

    This notably applies to foreign key constraints, since those are implemented by triggers.

  • Include user-specified trigger arguments when copying a trigger definition from a partitioned table to one of its partitions (Patrick McHardy)

  • Install dependencies to prevent dropping partition key columns (Tom Lane)

    ALTER TABLE ... DROP COLUMN will refuse to drop a column that is a partition key column. However, indirect drops (such as a cascade from dropping a key column's data type) had no such check, allowing the deletion of a key column. This resulted in a badly broken partitioned table that could neither be accessed nor dropped.

    This fix adds pg_depend entries that enforce that the whole partitioned table, not just the key column, will be dropped if a cascaded drop forces removal of the key column. However, such entries will only be created when a partitioned table is created; so this fix does not remove the risk for pre-existing partitioned tables. The issue can only arise for partition key columns of non-built-in data types, so it seems not to be a hazard for most users.

  • Ensure that column numbers are correctly mapped between a partitioned table and its default partition (Amit Langote)

    Some operations misbehaved if the mapping wasn't exactly one-to-one, for example if there were dropped columns in one table and not the other.

  • Ignore partitions that are foreign tables when creating indexes on partitioned tables (Álvaro Herrera)

    Previously an error was thrown on encountering a foreign-table partition, but that's unhelpful and doesn't protect against any actual problem.

  • Prune a partitioned table's default partition (that is, avoid uselessly scanning it) in more cases (Yuzuko Hosoya)

  • Fix possible failure to prune partitions when there are multiple partition key columns of boolean type (David Rowley)

  • Don't optimize away GROUP BY columns when the table involved is an inheritance parent (David Rowley)

    Normally, if a table's primary key column(s) are included in GROUP BY, it's safe to drop any other grouping columns, since the primary key columns are enough to make the groups unique. This rule does not work if the query is also reading inheritance child tables, though; the parent's uniqueness does not extend to the children.

  • Avoid incorrect use of parallel hash join for semi-join queries (Thomas Munro)

    This error resulted in duplicate result rows from some EXISTS queries.

  • Avoid using unnecessary sort steps for some queries with GROUPING SETS (Andrew Gierth, Richard Guo)

  • Fix possible failure of planner's index endpoint probes (Tom Lane)

    When using a recently-created index to determine the minimum or maximum value of a column, the planner could select a recently-dead tuple that does not actually contain the endpoint value. In the worst case the tuple might contain a null, resulting in a visible error “found unexpected null value in index”; more likely we would just end up using the wrong value, degrading the quality of planning estimates.

  • Fix failure to access trigger transition tables during EvalPlanQual rechecks (Alex Aktsipetrov)

    Triggers that rely on transition tables sometimes failed in the presence of concurrent updates.

  • Fix mishandling of multi-column foreign keys when rebuilding a foreign key constraint (Tom Lane)

    ALTER TABLE could make an incorrect decision about whether revalidation of a foreign key is necessary, if not all columns of the key are of the same type. It seems likely that the error would always have been in the conservative direction, that is revalidating unnecessarily.

  • Don't build extended statistics for inheritance trees (Tomas Vondra)

    This avoids a “tuple already updated by self” error during ANALYZE.

  • Avoid spurious deadlock errors when upgrading a tuple lock (Oleksii Kliukin)

    When two or more transactions are waiting for a transaction T1 to release a tuple-level lock, and T1 upgrades its lock to a higher level, a spurious deadlock among the waiting transactions could be reported when T1 finishes.

  • Fix failure to resolve deadlocks involving multiple parallel worker processes (Rui Hai Jiang)

    It is not clear whether this bug is reachable with non-artificial queries, but if it did happen, the queries involved in an otherwise-resolvable deadlock would block until canceled.

  • Prevent incorrect canonicalization of date ranges with infinity endpoints (Laurenz Albe)

    It's incorrect to try to convert an open range to a closed one or vice versa by incrementing or decrementing the endpoint value, if the endpoint is infinite; so leave the range alone in such cases.

  • Fix loss of fractional digits when converting very large money values to numeric (Tom Lane)

  • Fix printing of BTREE_META_CLEANUP WAL records (Michael Paquier)

  • Prevent assertion failures due to mishandling of version-2 btree metapages (Peter Geoghegan)

  • Fix spinlock assembly code for MIPS CPUs so that it works on MIPS r6 (YunQiang Su)

  • Ensure that a record or row value returned from a PL/pgSQL function is marked with the function's declared composite type (Tom Lane)

    This avoids problems if the result is stored directly into a table.

  • Make libpq ignore carriage return (\r) in connection service files (Tom Lane, Michael Paquier)

    In some corner cases, service files containing Windows-style newlines could be mis-parsed, resulting in connection failures.

  • In psql, avoid offering incorrect tab completion options after SET variable = (Tom Lane)

  • Fix a small memory leak in psql's \d command (Tom Lane)

  • Fix pg_dump to ensure that custom operator classes are dumped in the right order (Tom Lane)

    If a user-defined opclass is the subtype opclass of a user-defined range type, related objects were dumped in the wrong order, producing an unrestorable dump. (The underlying failure to handle opclass dependencies might manifest in other cases too, but this is the only known case.)

  • Fix possible lockup in pgbench when using -R option (Fabien Coelho)

  • Improve reliability of contrib/amcheck's index verification (Peter Geoghegan)

  • Fix handling of Perl undef values in contrib/jsonb_plperl (Ivan Panchenko)

  • Fix contrib/passwordcheck to coexist with other users of check_password_hook (Michael Paquier)

  • Fix contrib/sepgsql tests to work under recent SELinux releases (Mike Palmiotto)

  • Improve stability of src/test/kerberos and src/test/ldap regression tests (Thomas Munro, Tom Lane)

  • Improve stability of src/test/recovery regression tests (Michael Paquier)

  • Reduce stderr output from pg_upgrade's test script (Tom Lane)

  • Fix pgbench regression tests to work on Windows (Fabien Coelho)

  • Fix TAP tests to work with msys Perl, in cases where the build directory is on a non-root msys mount point (Noah Misch)

  • Support building Postgres with Microsoft Visual Studio 2019 (Haribabu Kommi)

  • In Visual Studio builds, honor WindowsSDKVersion environment variable, if that's set (Peifeng Qiu)

    This fixes build failures in some configurations.

  • Support OpenSSL 1.1.0 and newer in Visual Studio builds (Juan José Santamaría Flecha, Michael Paquier)

  • Allow make options to be passed down to gmake when non-GNU make is invoked at the top level (Thomas Munro)

  • Avoid choosing localtime or posixrules as TimeZone during initdb (Tom Lane)

    In some cases initdb would choose one of these artificial zone names over the “real” zone name. Prefer any other match to the C library's timezone behavior over these two.

  • Adjust pg_timezone_names view to show the Factory time zone if and only if it has a short abbreviation (Tom Lane)

    Historically, IANA set up this artificial zone with an “abbreviation” like Local time zone must be set--see zic manual page. Modern versions of the tzdb database show -00 instead, but some platforms alter the data to show one or another of the historical phrases. Show this zone only if it uses the modern abbreviation.

  • Sync our copy of the timezone library with IANA tzcode release 2019b (Tom Lane)

    This adds support for zic's new -b slim option to reduce the size of the installed zone files. We are not currently using that, but may enable it in future.

  • Update time zone data files to tzdata release 2019b for DST law changes in Brazil, plus historical corrections for Hong Kong, Italy, and Palestine.

• ⇑ Upgrade to 12 released on 2019-10-03 - docs

  • Remove the special behavior of oid columns (Andres Freund, John Naylor)

    Previously, a normally-invisible oid column could be specified during table creation using WITH OIDS; that ability has been removed. Columns can still be explicitly declared as type oid. Operations on tables that have columns created using WITH OIDS will need adjustment.

    The system catalogs that previously had hidden oid columns now have ordinary oid columns. Hence, SELECT * will now output those columns, whereas previously they would be displayed only if selected explicitly.

  • Remove data types abstime, reltime, and tinterval (Andres Freund)

    These are obsoleted by SQL-standard types such as timestamp.

  • Remove the timetravel extension (Andres Freund)

  • Move recovery.conf settings into postgresql.conf (Masao Fujii, Simon Riggs, Abhijit Menon-Sen, Sergei Kornilov)

    recovery.conf is no longer used, and the server will not start if that file exists. recovery.signal and standby.signal files are now used to switch into non-primary mode. The trigger_file setting has been renamed to promote_trigger_file. The standby_mode setting has been removed.

  • Do not allow multiple conflicting recovery_target* specifications (Peter Eisentraut)

    Specifically, only allow one of recovery_target, recovery_target_lsn, recovery_target_name, recovery_target_time, and recovery_target_xid. Previously, multiple different instances of these parameters could be specified, and the last one was honored. Now, only one can be specified, though the same one can be specified multiple times and the last specification is honored.

  • Cause recovery to advance to the latest timeline by default (Peter Eisentraut)

    Specifically, recovery_target_timeline now defaults to latest. Previously, it defaulted to current.

  • Refactor code for geometric functions and operators (Emre Hasegeli)

    This could lead to more accurate, but slightly different, results compared to previous releases. Notably, cases involving NaN, underflow, overflow, and division by zero are handled more consistently than before.

  • Improve performance by using a new algorithm for output of real and double precision values (Andrew Gierth)

    Previously, displayed floating-point values were rounded to 6 (for real) or 15 (for double precision) digits by default, adjusted by the value of extra_float_digits. Now, whenever extra_float_digits is more than zero (as it now is by default), only the minimum number of digits required to preserve the exact binary value are output. The behavior is the same as before when extra_float_digits is set to zero or less.

    Also, formatting of floating-point exponents is now uniform across platforms: two digits are used unless three are necessary. In previous releases, Windows builds always printed three digits.

  • random() and setseed() now behave uniformly across platforms (Tom Lane)

    The sequence of random() values generated following a setseed() call with a particular seed value is likely to be different now than before. However, it will also be repeatable, which was not previously guaranteed because of interference from other uses of random numbers inside the server. The SQL random() function now has its own private per-session state to forestall that.

  • Change SQL-style substring() to have standard-compliant greediness behavior (Tom Lane)

    In cases where the pattern can be matched in more than one way, the initial sub-pattern is now treated as matching the least possible amount of text rather than the greatest; for example, a pattern such as %#"aa*#"% now selects the first group of a's from the input, not the last group.

  • Do not pretty-print the result of xpath() or the XMLTABLE construct (Tom Lane)

    In some cases, these functions would insert extra whitespace (newlines and/or spaces) in nodeset values. This is undesirable since depending on usage, the whitespace might be considered semantically significant.

  • Rename command-line tool pg_verify_checksums to pg_checksums (Michaël Paquier)

  • In pg_restore, require specification of -f - to send the dump contents to standard output (Euler Taveira)

    Previously, this happened by default if no destination was specified, but that was deemed to be unfriendly.

  • Disallow non-unique abbreviations in psql's \pset format command (Daniel Vérité)

    Previously, for example, \pset format a chose aligned; it will now fail since that could equally well mean asciidoc.

  • In new btree indexes, the maximum index entry length is reduced by eight bytes, to improve handling of duplicate entries (Peter Geoghegan)

    This means that a REINDEX operation on an index pg_upgrade'd from a previous release could potentially fail.

  • Cause DROP IF EXISTS FUNCTION/PROCEDURE/AGGREGATE/ROUTINE to generate an error if no argument list is supplied and there are multiple matching objects (David Rowley)

    Also improve the error message in such cases.

  • Split the pg_statistic_ext catalog into two catalogs, and add the pg_stats_ext view of it (Dean Rasheed, Tomas Vondra)

    This change supports hiding potentially-sensitive statistics data from unprivileged users.

  • Remove obsolete pg_constraint.consrc column (Peter Eisentraut)

  • Remove obsolete pg_attrdef.adsrc column (Peter Eisentraut)

  • Mark table columns of type name as having “C” collation by default (Tom Lane, Daniel Vérité)

    The comparison operators for data type name can now use any collation, rather than always using “C” collation. To preserve the previous semantics of queries, columns of type name are now explicitly marked as having “C” collation. A side effect of this is that regular-expression operators on name columns will now use the “C” collation by default, not the database collation, to determine the behavior of locale-dependent regular expression patterns (such as \w). If you want non-C behavior for a regular expression on a name column, attach an explicit COLLATE clause. (For user-defined name columns, another possibility is to specify a different collation at table creation time; but that just moves the non-backwards-compatibility to the comparison operators.)

  • Treat object-name columns in the information_schema views as being of type name, not varchar (Tom Lane)

    Per the SQL standard, object-name columns in the information_schema views are declared as being of domain type sql_identifier. In PostgreSQL, the underlying catalog columns are really of type name. This change makes sql_identifier be a domain over name, rather than varchar as before. This eliminates a semantic mismatch in comparison and sorting behavior, which can greatly improve the performance of queries on information_schema views that restrict an object-name column. Note however that inequality restrictions, for example

    SELECT ... FROM information_schema.tables WHERE table_name < 'foo';
    

    will now use “C”-locale comparison semantics by default, rather than the database's default collation as before. Sorting on these columns will also follow “C” ordering rules. The previous behavior (and inefficiency) can be enforced by adding a COLLATE "default" clause.

  • Remove the ability to disable dynamic shared memory (Kyotaro Horiguchi)

    Specifically, dynamic_shared_memory_type can no longer be set to none.

  • Parse libpq integer connection parameters more strictly (Fabien Coelho)

    In previous releases, using an incorrect integer value for connection parameters connect_timeout, keepalives, keepalives_count, keepalives_idle, keepalives_interval and port resulted in libpq either ignoring those values or failing with incorrect error messages.

  • Improve performance of many operations on partitioned tables (Amit Langote, David Rowley, Tom Lane, Álvaro Herrera)

    Allow tables with thousands of child partitions to be processed efficiently by operations that only affect a small number of partitions.

  • Allow foreign keys to reference partitioned tables (Álvaro Herrera)

  • Improve speed of COPY into partitioned tables (David Rowley)

  • Allow partition bounds to be any expression (Kyotaro Horiguchi, Tom Lane, Amit Langote)

    Such expressions are evaluated at partitioned-table creation time. Previously, only simple constants were allowed as partition bounds.

  • Allow CREATE TABLE's tablespace specification for a partitioned table to affect the tablespace of its children (David Rowley, Álvaro Herrera)

  • Avoid sorting when partitions are already being scanned in the necessary order (David Rowley)

  • ALTER TABLE ATTACH PARTITION is now performed with reduced locking requirements (Robert Haas)

  • Add partition introspection functions (Michaël Paquier, Álvaro Herrera, Amit Langote)

    The new function pg_partition_root() returns the top-most parent of a partition tree, pg_partition_ancestors() reports all ancestors of a partition, and pg_partition_tree() displays information about partitions.

  • Include partitioned indexes in the system view pg_indexes (Suraj Kharage)

  • Add psql command \dP to list partitioned tables and indexes (Pavel Stehule)

  • Improve psql \d and \z display of partitioned tables (Pavel Stehule, Michaël Paquier, Álvaro Herrera)

  • Fix bugs that could cause ALTER TABLE DETACH PARTITION to leave behind incorrect dependency state, allowing subsequent operations to misbehave, for example by not dropping a former partition child index when its table is dropped (Tom Lane)

  • Improve performance and space utilization of btree indexes with many duplicates (Peter Geoghegan, Heikki Linnakangas)

    Previously, duplicate index entries were stored unordered within their duplicate groups. This caused overhead during index inserts, wasted space due to excessive page splits, and it reduced VACUUM's ability to recycle entire pages. Duplicate index entries are now sorted in heap-storage order.

    Indexes pg_upgrade'd from previous releases will not have these benefits.

  • Allow multi-column btree indexes to be smaller (Peter Geoghegan, Heikki Linnakangas)

    Internal pages and min/max leaf page indicators now only store index keys until the change key, rather than all indexed keys. This also improves the locality of index access.

    Indexes pg_upgrade'd from previous releases will not have these benefits.

  • Improve speed of btree index insertions by reducing locking overhead (Alexander Korotkov)

  • Support INCLUDE columns in GiST indexes (Andrey Borodin)

  • Add support for nearest-neighbor (KNN) searches of SP-GiST indexes (Nikita Glukhov, Alexander Korotkov, Vlad Sterzhanov)

  • Reduce the WAL write overhead of GiST, GIN, and SP-GiST index creation (Anastasia Lubennikova, Andrey V. Lepikhov)

  • Allow index-only scans to be more efficient on indexes with many columns (Konstantin Knizhnik)

  • Improve the performance of vacuum scans of GiST indexes (Andrey Borodin, Konstantin Kuznetsov, Heikki Linnakangas)

  • Delete empty leaf pages during GiST VACUUM (Andrey Borodin)

  • Reduce locking requirements for index renaming (Peter Eisentraut)

  • Allow CREATE STATISTICS to create most-common-value statistics for multiple columns (Tomas Vondra)

    This improves optimization for queries that test several columns, requiring an estimate of the combined effect of several WHERE clauses. If the columns are correlated and have non-uniform distributions then multi-column statistics will allow much better estimates.

  • Allow common table expressions (CTEs) to be inlined into the outer query (Andreas Karlsson, Andrew Gierth, David Fetter, Tom Lane)

    Specifically, CTEs are automatically inlined if they have no side-effects, are not recursive, and are referenced only once in the query. Inlining can be prevented by specifying MATERIALIZED, or forced for multiply-referenced CTEs by specifying NOT MATERIALIZED. Previously, CTEs were never inlined and were always evaluated before the rest of the query.

  • Allow control over when generic plans are used for prepared statements (Pavel Stehule)

    This is controlled by the plan_cache_mode server parameter.

  • Improve optimization of partition and UNION ALL queries that have only a single child (David Rowley)

  • Improve processing of domains that have no check constraints (Tom Lane)

    Domains that are being used purely as type aliases no longer cause optimization difficulties.

  • Pre-evaluate calls of LEAST and GREATEST when their arguments are constants (Vik Fearing)

  • Improve optimizer's ability to verify that partial indexes with IS NOT NULL conditions are usable in queries (Tom Lane, James Coleman)

    Usability can now be recognized in more cases where the calling query involves casts or large x IN (array) clauses.

  • Compute ANALYZE statistics using the collation defined for each column (Tom Lane)

    Previously, the database's default collation was used for all statistics. This potentially gives better optimizer behavior for columns with non-default collations.

  • Improve selectivity estimates for inequality comparisons on ctid columns (Edmund Horner)

  • Improve optimization of joins on columns of type tid (Tom Lane)

    These changes primarily improve the efficiency of self-joins on ctid columns.

  • Fix the leakproofness designations of some btree comparison operators and support functions (Tom Lane)

    This allows some optimizations that previously would not have been applied in the presence of security barrier views or row-level security.

  • Enable Just-in-Time (JIT) compilation by default, if the server has been built with support for it (Andres Freund)

    Note that this support is not built by default, but has to be selected explicitly while configuring the build.

  • Speed up keyword lookup (John Naylor, Joerg Sonnenberger, Tom Lane)

  • Improve search performance for multi-byte characters in position() and related functions (Heikki Linnakangas)

  • Allow toasted values to be minimally decompressed (Paul Ramsey)

    This is useful for routines that only need to examine the initial portion of a toasted field.

  • Allow ALTER TABLE ... SET NOT NULL to avoid unnecessary table scans (Sergei Kornilov)

    This can be optimized when the table's column constraints can be recognized as disallowing nulls.

  • Allow ALTER TABLE ... SET DATA TYPE changing between timestamp and timestamptz to avoid a table rewrite when the session time zone is UTC (Noah Misch)

    In the UTC time zone, these two data types are binary compatible.

  • Improve speed in converting strings to int2 or int4 integers (Andres Freund)

  • Allow parallelized queries when in SERIALIZABLE isolation mode (Thomas Munro)

    Previously, parallelism was disabled when in this mode.

  • Use pread() and pwrite() for random I/O (Oskari Saarenmaa, Thomas Munro)

    This reduces the number of system calls required for I/O.

  • Improve the speed of setting the process title on FreeBSD (Thomas Munro)

  • Allow logging of statements from only a percentage of transactions (Adrien Nayrat)

    The parameter log_transaction_sample_rate controls this.

  • Add progress reporting to CREATE INDEX and REINDEX operations (Álvaro Herrera, Peter Eisentraut)

    Progress is reported in the pg_stat_progress_create_index system view.

  • Add progress reporting to CLUSTER and VACUUM FULL (Tatsuro Yamada)

    Progress is reported in the pg_stat_progress_cluster system view.

  • Add progress reporting to pg_checksums (Michael Banck, Bernd Helmle)

    This is enabled with the option --progress.

  • Add counter of checksum failures to pg_stat_database (Magnus Hagander)

  • Add tracking of global objects in system view pg_stat_database (Julien Rouhaud)

    Global objects are shown with a pg_stat_database.datid value of zero.

  • Add the ability to list the contents of the archive directory (Christoph Moench-Tegeder)

    The function is pg_ls_archive_statusdir().

  • Add the ability to list the contents of temporary directories (Nathan Bossart)

    The function, pg_ls_tmpdir(), optionally allows specification of a tablespace.

  • Add information about the client certificate to the system view pg_stat_ssl (Peter Eisentraut)

    The new columns are client_serial and issuer_dn. Column clientdn has been renamed to client_dn for clarity.

  • Restrict visibility of rows in pg_stat_ssl for unprivileged users (Peter Eisentraut)

  • At server start, emit a log message including the server version number (Christoph Berg)

  • Prevent logging “incomplete startup packet” if a new connection is immediately closed (Tom Lane)

    This avoids log spam from certain forms of monitoring.

  • Include the application_name, if set, in log_connections log messages (Don Seiler)

  • Make the walreceiver set its application name to the cluster name, if set (Peter Eisentraut)

  • Add the timestamp of the last received standby message to pg_stat_replication (Lim Myungkyu)

  • Add a wait event for fsync of WAL segments (Konstantin Knizhnik)

  • Add GSSAPI encryption support (Robbie Harwood, Stephen Frost)

    This feature allows TCP/IP connections to be encrypted when using GSSAPI authentication, without having to set up a separate encryption facility such as SSL. In support of this, add hostgssenc and hostnogssenc record types in pg_hba.conf for selecting connections that do or do not use GSSAPI encryption, corresponding to the existing hostssl and hostnossl record types. There is also a new gssencmode libpq option, and a pg_stat_gssapi system view.

  • Allow the clientcert pg_hba.conf option to check that the database user name matches the client certificate's common name (Julian Markwort, Marius Timmer)

    This new check is enabled with clientcert=verify-full.

  • Allow discovery of an LDAP server using DNS SRV records (Thomas Munro)

    This avoids the requirement of specifying ldapserver. It is only supported if PostgreSQL is compiled with OpenLDAP.

  • Add ability to enable/disable cluster checksums using pg_checksums (Michael Banck, Michaël Paquier)

    The cluster must be shut down for these operations.

  • Reduce the default value of autovacuum_vacuum_cost_delay to 2ms (Tom Lane)

    This allows autovacuum operations to proceed faster by default.

  • Allow vacuum_cost_delay to specify sub-millisecond delays, by accepting fractional values (Tom Lane)

  • Allow time-based server parameters to use units of microseconds (us) (Tom Lane)

  • Allow fractional input for integer server parameters (Tom Lane)

    For example, SET work_mem = '30.1GB' is now allowed, even though work_mem is an integer parameter. The value will be rounded to an integer after any required units conversion.

  • Allow units to be defined for floating-point server parameters (Tom Lane)

  • Add wal_recycle and wal_init_zero server parameters to control WAL file recycling (Jerry Jelinek)

    Avoiding file recycling can be beneficial on copy-on-write file systems like ZFS.

  • Add server parameter tcp_user_timeout to control the server's TCP timeout (Ryohei Nagaura)

  • Allow control of the minimum and maximum SSL protocol versions (Peter Eisentraut)

    The server parameters are ssl_min_protocol_version and ssl_max_protocol_version.

  • Add server parameter ssl_library to report the SSL library version used by the server (Peter Eisentraut)

  • Add server parameter shared_memory_type to control the type of shared memory to use (Andres Freund)

    This allows selection of System V shared memory, if desired.

  • Allow some recovery parameters to be changed with reload (Peter Eisentraut)

    These parameters are archive_cleanup_command, promote_trigger_file, recovery_end_command, and recovery_min_apply_delay.

  • Allow the streaming replication timeout (wal_sender_timeout) to be set per connection (Takayuki Tsunakawa)

    Previously, this could only be set cluster-wide.

  • Add function pg_promote() to promote standbys to primaries (Laurenz Albe, Michaël Paquier)

    Previously, this operation was only possible by using pg_ctl or creating a trigger file.

  • Allow replication slots to be copied (Masahiko Sawada)

    The functions for this are pg_copy_physical_replication_slot() and pg_copy_logical_replication_slot().

  • Make max_wal_senders not count as part of max_connections (Alexander Kukushkin)

  • Add an explicit value of current for recovery_target_timeline (Peter Eisentraut)

  • Make recovery fail if a two-phase transaction status file is corrupt (Michaël Paquier)

    Previously, a warning was logged and recovery continued, allowing the transaction to be lost.

  • Add REINDEX CONCURRENTLY option to allow reindexing without locking out writes (Michaël Paquier, Andreas Karlsson, Peter Eisentraut)

    This is also controlled by the reindexdb application's --concurrently option.

  • Add support for generated columns (Peter Eisentraut)

    The content of generated columns are computed from expressions (including references to other columns in the same table) rather than being specified by INSERT or UPDATE commands.

  • Add a WHERE clause to COPY FROM to control which rows are accepted (Surafel Temesgen)

    This provides a simple way to filter incoming data.

  • Allow enumerated values to be added more flexibly (Andrew Dunstan, Tom Lane, Thomas Munro)

    Previously, ALTER TYPE ... ADD VALUE could not be called in a transaction block, unless it was part of the same transaction that created the enumerated type. Now it can be called in a later transaction, so long as the new enumerated value is not referenced until after it is committed.

  • Add commands to end a transaction and start a new one (Peter Eisentraut)

    The commands are COMMIT AND CHAIN and ROLLBACK AND CHAIN.

  • Add VACUUM and CREATE TABLE options to prevent VACUUM from truncating trailing empty pages (Takayuki Tsunakawa)

    These options are vacuum_truncate and toast.vacuum_truncate. Use of these options reduces VACUUM's locking requirements, but prevents returning disk space to the operating system.

  • Allow VACUUM to skip index cleanup (Masahiko Sawada)

    This change adds a VACUUM command option INDEX_CLEANUP as well as a table storage option vacuum_index_cleanup. Use of this option reduces the ability to reclaim space and can lead to index bloat, but it is helpful when the main goal is to freeze old tuples.

  • Add the ability to skip VACUUM and ANALYZE operations on tables that cannot be locked immediately (Nathan Bossart)

    This option is called SKIP_LOCKED.

  • Allow VACUUM and ANALYZE to take optional Boolean argument specifications (Masahiko Sawada)

  • Prevent TRUNCATE, VACUUM and ANALYZE from requesting a lock on tables for which the user lacks permission (Michaël Paquier)

    This prevents unauthorized locking, which could interfere with user queries.

  • Add EXPLAIN option SETTINGS to output non-default optimizer settings (Tomas Vondra)

    This output can also be obtained when using auto_explain by setting auto_explain.log_settings.

  • Add OR REPLACE option to CREATE AGGREGATE (Andrew Gierth)

  • Allow modifications of system catalogs' options using ALTER TABLE (Peter Eisentraut)

    Modifications of catalogs' reloptions and autovacuum settings are now supported. (Setting allow_system_table_mods is still required.)

  • Use all key columns' names when selecting default constraint names for foreign keys (Peter Eisentraut)

    Previously, only the first column name was included in the constraint name, resulting in ambiguity for multi-column foreign keys.

  • Update assorted knowledge about Unicode to match Unicode 12.1.0 (Peter Eisentraut)

    This fixes, for example, cases where psql would misformat output involving combining characters.

  • Update Snowball stemmer dictionaries with support for new languages (Arthur Zakirov)

    This adds word stemming support for Arabic, Indonesian, Irish, Lithuanian, Nepali, and Tamil to full text search.

  • Allow creation of collations that report string equality for strings that are not bit-wise equal (Peter Eisentraut)

    This feature supports “nondeterministic” collations that can define case- and accent-agnostic equality comparisons. Thus, for example, a case-insensitive uniqueness constraint on a text column can be made more easily than before. This is only supported for ICU collations.

  • Add support for ICU collation attributes on older ICU versions (Peter Eisentraut)

    This allows customization of the collation rules in a consistent way across all ICU versions.

  • Allow data type name to more seamlessly be compared to other text types (Tom Lane)

    Type name now behaves much like a domain over type text that has default collation “C”. This allows cross-type comparisons to be processed more efficiently.

  • Add support for the SQL/JSON path language (Nikita Glukhov, Teodor Sigaev, Alexander Korotkov, Oleg Bartunov, Liudmila Mantrova)

    This allows execution of complex queries on JSON values using an SQL-standard language.

  • Add support for hyperbolic functions (Lætitia Avrot)

    Also add log10() as an alias for log(), for standards compliance.

  • Improve the accuracy of statistical aggregates like variance() by using more precise algorithms (Dean Rasheed)

  • Allow date_trunc() to have an additional argument to control the time zone (Vik Fearing, Tom Lane)

    This is faster and simpler than using the AT TIME ZONE clause.

  • Adjust to_timestamp()/to_date() functions to be more forgiving of template mismatches (Artur Zakirov, Alexander Korotkov, Liudmila Mantrova)

    This new behavior more closely matches the Oracle functions of the same name.

  • Fix assorted bugs in XML functions (Pavel Stehule, Markus Winand, Chapman Flack)

    Specifically, in XMLTABLE, xpath(), and xmlexists(), fix some cases where nothing was output for a node, or an unexpected error was thrown, or necessary escaping of XML special characters was omitted.

  • Allow the BY VALUE clause in XMLEXISTS and XMLTABLE (Chapman Flack)

    This SQL-standard clause has no effect in PostgreSQL's implementation, but it was unnecessarily being rejected.

  • Prevent current_schema() and current_schemas() from being run by parallel workers, as they are not parallel-safe (Michaël Paquier)

  • Allow RECORD and RECORD[] to be used as column types in a query's column definition list for a table function that is declared to return RECORD (Elvis Pranskevichus)

  • Allow SQL commands and variables with the same names as those commands to be used in the same PL/pgSQL function (Tom Lane)

    For example, allow a variable called comment to exist in a function that calls the COMMENT SQL command. Previously this combination caused a parse error.

  • Add new optional warning and error checks to PL/pgSQL (Pavel Stehule)

    The new checks allow for run-time validation of INTO column counts and single-row results.

  • Add connection parameter tcp_user_timeout to control libpq's TCP timeout (Ryohei Nagaura)

  • Allow libpq (and thus psql) to report only the SQLSTATE value in error messages (Didier Gautheron)

  • Add libpq function PQresultMemorySize() to report the memory used by a query result (Lars Kanis, Tom Lane)

  • Remove the no-display/debug flag from libpq's options connection parameter (Peter Eisentraut)

    This allows this parameter to be set by postgres_fdw.

  • Allow ecpg to create variables of data type bytea (Ryo Matsumura)

    This allows ECPG clients to interact with bytea data directly, rather than using an encoded form.

  • Add PREPARE AS support to ECPG (Ryo Matsumura)

  • Allow vacuumdb to select tables for vacuum based on their wraparound horizon (Nathan Bossart)

    The options are --min-xid-age and --min-mxid-age.

  • Allow vacuumdb to disable waiting for locks or skipping all-visible pages (Nathan Bossart)

    The options are --skip-locked and --disable-page-skipping.

  • Add colorization to the output of command-line utilities (Peter Eisentraut)

    This is enabled by setting the environment variable PG_COLOR to always or auto. The specific colors used can be adjusted by setting the environment variable PG_COLORS, using ANSI escape codes for colors. For example, the default behavior is equivalent to PG_COLORS="error=01;31:warning=01;35:locus=01".

  • Add CSV table output mode in psql (Daniel Vérité)

    This is controlled by \pset format csv or the command-line --csv option.

  • Show the manual page URL in psql's \help output for a SQL command (Peter Eisentraut)

  • Display the IP address in psql's \conninfo (Fabien Coelho)

  • Improve tab completion of CREATE TABLE, CREATE TRIGGER, CREATE EVENT TRIGGER, ANALYZE, EXPLAIN, VACUUM, ALTER TABLE, ALTER INDEX, ALTER DATABASE, and ALTER INDEX ALTER COLUMN (Dagfinn Ilmari Mannsåker, Tatsuro Yamada, Michaël Paquier, Tom Lane, Justin Pryzby)

  • Allow values produced by queries to be assigned to pgbench variables (Fabien Coelho, Álvaro Herrera)

    The command for this is \gset.

  • Improve precision of pgbench's --rate option (Tom Lane)

  • Improve pgbench's error reporting with clearer messages and return codes (Peter Eisentraut)

  • Allow control of log file rotation via pg_ctl (Kyotaro Horiguchi, Alexander Kuzmenkov, Alexander Korotkov)

    Previously, this was only possible via an SQL function or a process signal.

  • Properly detach the new server process during pg_ctl start (Paul Guo)

    This prevents the server from being shut down if the shell script that invoked pg_ctl is interrupted later.

  • Allow pg_upgrade to use the file system's cloning feature, if there is one (Peter Eisentraut)

    The --clone option has the advantages of --link, while preventing the old cluster from being changed after the new cluster has started.

  • Allow specification of the socket directory to use in pg_upgrade (Daniel Gustafsson)

    This is controlled by --socketdir; the default is the current directory.

  • Allow pg_checksums to disable fsync operations (Michaël Paquier)

    This is controlled by the --no-sync option.

  • Allow pg_rewind to disable fsync operations (Michaël Paquier)

  • Fix pg_test_fsync to report accurate open_datasync durations on Windows (Laurenz Albe)

  • When pg_dump emits data with INSERT commands rather than COPY, allow more than one data row to be included in each INSERT (Surafel Temesgen, David Rowley)

    The option controlling this is --rows-per-insert.

  • Allow pg_dump to emit INSERT ... ON CONFLICT DO NOTHING (Surafel Temesgen)

    This avoids conflict failures during restore. The option is --on-conflict-do-nothing.

  • Decouple the order of operations in a parallel pg_dump from the order used by a subsequent parallel pg_restore (Tom Lane)

    This allows pg_restore to perform more-fully-parallelized parallel restores, especially in cases where the original dump was not done in parallel. Scheduling of a parallel pg_dump is also somewhat improved.

  • Allow the extra_float_digits setting to be specified for pg_dump and pg_dumpall (Andrew Dunstan)

    This is primarily useful for making dumps that are exactly comparable across different source server versions. It is not recommended for normal use, as it may result in loss of precision when the dump is restored.

  • Add --exclude-database option to pg_dumpall (Andrew Dunstan)

  • Add CREATE ACCESS METHOD command to create new table types (Andres Freund, Haribabu Kommi, Álvaro Herrera, Alexander Korotkov, Dmitry Dolgov)

    This enables the development of new table access methods, which can optimize storage for different use cases. The existing heap access method remains the default.

  • Add planner support function interfaces to improve optimizer estimates, inlining, and indexing for functions (Tom Lane)

    This allows extensions to create planner support functions that can provide function-specific selectivity, cost, and row-count estimates that can depend on the function's arguments. Support functions can also supply simplified representations and index conditions, greatly expanding optimization possibilities.

  • Simplify renumbering manually-assigned OIDs, and establish a new project policy for management of such OIDs (John Naylor, Tom Lane)

    Patches that manually assign OIDs for new built-in objects (such as new functions) should now randomly choose OIDs in the range 8000—9999. At the end of a development cycle, the OIDs used by committed patches will be renumbered down to lower numbers, currently somewhere in the 4xxx range, using the new renumber_oids.pl script. This approach should greatly reduce the odds of OID collisions between different in-process patches.

    While there is no specific policy reserving any OIDs for external use, it is recommended that forks and other projects needing private manually-assigned OIDs use numbers in the high 7xxx range. This will avoid conflicts with recently-merged patches, and it should be a long time before the core project reaches that range.

  • Build Cygwin binaries using dynamic instead of static libraries (Marco Atzeri)

  • Remove configure switch --disable-strong-random (Michaël Paquier)

    A strong random-number source is now required.

  • printf-family functions, as well as strerror and strerror_r, now behave uniformly across platforms within Postgres code (Tom Lane)

    Notably, printf understands %m everywhere; on Windows, strerror copes with Winsock error codes (it used to do so in backend but not frontend code); and strerror_r always follows the GNU return convention.

  • Require a C99-compliant compiler, and MSVC 2013 or later on Windows (Andres Freund)

  • Use pandoc, not lynx, for generating plain-text documentation output files (Peter Eisentraut)

    This affects only the INSTALL file generated during make dist and the seldom-used plain-text postgres.txt output file. Pandoc produces better output than lynx and avoids some locale/encoding issues. Pandoc version 1.13 or later is required.

  • Support use of images in the PostgreSQL documentation (Jürgen Purtz)

  • Allow ORDER BY sorts and LIMIT clauses to be pushed to postgres_fdw foreign servers in more cases (Etsuro Fujita)

  • Improve optimizer cost accounting for postgres_fdw queries (Etsuro Fujita)

  • Properly honor WITH CHECK OPTION on views that reference postgres_fdw tables (Etsuro Fujita)

    While CHECK OPTIONs on postgres_fdw tables are ignored (because the reference is foreign), views on such tables are considered local, so this change enforces CHECK OPTIONs on them. Previously, only INSERTs and UPDATEs with RETURNING clauses that returned CHECK OPTION values were validated.

  • Allow pg_stat_statements_reset() to be more granular (Haribabu Kommi, Amit Kapila)

    The function now allows reset of statistics for specific databases, users, and queries.

  • Allow control of the auto_explain log level (Tom Dunstan, Andrew Dunstan)

    The default is LOG.

  • Update unaccent rules with new punctuation and symbols (Hugh Ranalli, Michaël Paquier)

  • Allow unaccent to handle some accents encoded as combining characters (Hugh Ranalli)

  • Allow unaccent to remove accents from Greek characters (Tasos Maschalidis)

  • Add a parameter to amcheck's bt_index_parent_check() function to check each index tuple from the root of the tree (Peter Geoghegan)

  • Improve oid2name and vacuumlo option handling to match other commands (Tatsuro Yamada)

• ⇑ Upgrade to 12.1 released on 2019-11-14 - docs

  • Fix crash when ALTER TABLE adds a column without a default value along with making other changes that require a table rewrite (Andres Freund)

  • Fix lock handling in REINDEX CONCURRENTLY (Michael Paquier)

    REINDEX CONCURRENTLY neglected to take a session-level lock on the new index version, potentially allowing other sessions to manipulate it too soon. Also, a query-cancel or session-termination interrupt arriving at the wrong time could result in failure to release the session-level locks that REINDEX CONCURRENTLY does hold.

  • Avoid crash due to race condition when reporting the progress of a CREATE INDEX CONCURRENTLY or REINDEX CONCURRENTLY command (Álvaro Herrera)

  • Avoid creating duplicate dependency entries during REINDEX CONCURRENTLY (Michael Paquier)

    This bug resulted in bloat in pg_depend, but no worse consequences than that.

  • Prevent VACUUM from trying to freeze an old multixact ID involving a still-running transaction (Nathan Bossart, Jeremy Schneider)

    This case would lead to VACUUM failing until the old transaction terminates.

  • Fix “wrong type of slot” error when trying to CLUSTER on an expression index (Andres Freund)

  • SET CONSTRAINTS ... DEFERRED failed on partitioned tables, incorrectly complaining about lack of triggers (Álvaro Herrera)

  • Fix failure when creating indexes for a partition, if the parent partitioned table contains any dropped columns (Michael Paquier)

  • Fix dropping of indexed columns in partitioned tables (Amit Langote, Michael Paquier)

    Previously this might fail with an error message complaining about the dependencies of the indexes. It should automatically drop the indexes, instead.

  • Ensure that a partition index can be dropped after a failure to reindex it concurrently (Michael Paquier)

    The index's pg_class.relispartition flag was left in the wrong state in such a case, causing DROP INDEX to fail.

  • Fix handling of equivalence class members for partition-wise joins (Amit Langote)

    This oversight could lead either to failure to use a feasible partition-wise join plan, or to a “could not find pathkey item to sort” planner failure.

  • Ensure that offset expressions in WINDOW clauses are processed when a query's expressions are manipulated (Andrew Gierth)

    This oversight could result in assorted failures when the offsets are nontrivial expressions. One example is that a function parameter reference in such an expression would fail if the function was inlined.

  • Avoid postmaster failure if a parallel query requests a background worker when no postmaster child process array slots remain free (Tom Lane)

  • Fix crash triggered by an EvalPlanQual recheck on a table with a BEFORE UPDATE trigger (Andres Freund)

  • Fix “unexpected relkind” error when a query tries to access a TOAST table (John Hsu, Michael Paquier, Tom Lane)

    The error should say that permission is denied, but this case got broken during code refactoring.

  • Provide a relevant error context line when an error occurs while setting GUC parameters during parallel worker startup (Thomas Munro)

  • Ensure that fsync() is applied only to files that are opened read/write (Andres Freund, Michael Paquier)

    Some code paths tried to do this after opening a file read-only, but on some platforms that causes “bad file descriptor” or similar errors.

  • Allow encoding conversion to succeed on longer strings than before (Álvaro Herrera, Tom Lane)

    Previously, there was a hard limit of 0.25GB on the input string, but now it will work as long as the converted output is not over 1GB.

  • Avoid creating unnecessarily-bulky tuple stores for window functions (Andrew Gierth)

    In some cases the tuple storage would include all columns of the source table(s), not just the ones that are needed by the query.

  • Allow repalloc() to give back space when a large chunk is reduced in size (Tom Lane)

  • Ensure that temporary WAL and history files are removed at the end of archive recovery (Sawada Masahiko)

  • Avoid failure in archive recovery if recovery_min_apply_delay is enabled (Fujii Masao)

    recovery_min_apply_delay is not typically used in this configuration, but it should work.

  • Ignore restore_command, recovery_end_command, and recovery_min_apply_delay settings during crash recovery (Fujii Masao)

    Now that these settings can be specified in postgresql.conf, they could be turned on during crash recovery, but honoring them then is undesirable. Ignore these settings until crash recovery is complete.

  • Fix logical replication failure when publisher and subscriber have different ideas about a table's replica identity columns (Jehan-Guillaume de Rorthais, Peter Eisentraut)

    Declaring a column as part of the replica identity on the subscriber, when it does not exist at all on the publisher, led to “negative bitmapset member not allowed” errors.

  • Avoid unwanted delay during shutdown of a logical replication walsender (Craig Ringer, Álvaro Herrera)

  • Fix timeout handling in logical replication walreceiver processes (Julien Rouhaud)

    Erroneous logic prevented wal_receiver_timeout from working in logical replication deployments.

  • Correctly time-stamp replication messages for logical decoding (Jeff Janes)

    This oversight resulted, for example, in pg_stat_subscription.last_msg_send_time usually reading as NULL.

  • Fix race condition during backend exit, when the backend process has previously waited for synchronous replication to occur (Dongming Liu)

  • Avoid logging complaints about abandoned connections when using PAM authentication (Tom Lane)

    libpq-based clients will typically make two connection attempts when a password is required, since they don't prompt their user for a password until their first connection attempt fails. Therefore the server is coded not to generate useless log spam when a client closes the connection upon being asked for a password. However, the PAM authentication code hadn't gotten that memo, and would generate several messages about a phantom authentication failure.

  • Fix misbehavior of bitshiftright() (Tom Lane)

    The bitstring right shift operator failed to zero out padding space that exists in the last byte of the result when the bitstring length is not a multiple of 8. While invisible to most operations, any nonzero bits there would result in unexpected comparison behavior, since bitstring comparisons don't bother to ignore the extra bits, expecting them to always be zero.

    If you have inconsistent data as a result of saving the output of bitshiftright() in a table, it's possible to fix it with something like

    UPDATE mytab SET bitcol = ~(~bitcol) WHERE bitcol != ~(~bitcol);
    

  • Fix result of text position() function (also known as strpos()) for an empty search string (Tom Lane)

    Historically, and per the SQL standard, the result should be one in such cases, but 12.0 returned zero.

  • Fix detection of edge-case integer overflow in interval multiplication (Yuya Watari)

  • Avoid crashes if ispell text search dictionaries contain wrong affix data (Arthur Zakirov)

  • Avoid memory leak while vacuuming a GiST index (Dilip Kumar)

  • On Windows, recognize additional spellings of the “Norwegian (Bokmål)” locale name (Tom Lane)

  • Fix libpq to allow trailing whitespace in the string values of integer parameters (Michael Paquier)

    Version 12 tightened libpq's validation of integer parameters, but disallowing trailing whitespace seems undesirable.

  • In libpq, correctly report CONNECTION_BAD connection status after a failure caused by a syntactically invalid connect_timeout parameter value (Lars Kanis)

  • Avoid compile failure if an ECPG client includes ecpglib.h while having ENABLE_NLS defined (Tom Lane)

    This risk was created by a misplaced declaration: ecpg_gettext() should not be visible to client code.

  • Fix scheduling of parallel restore of a foreign key constraint on a partitioned table (Álvaro Herrera)

    pg_dump failed to emit full dependency information for partitioned tables' foreign keys. This could allow parallel pg_restore to try to recreate a foreign key constraint too soon.

  • In pg_dump, ensure stable output order for similarly-named triggers and row-level-security policy objects (Benjie Gillam)

    Previously, if two triggers on different tables had the same names, they would be sorted in OID-based order, which is less desirable than sorting them by table name. Likewise for RLS policies.

  • In pg_upgrade, reject tables with columns of type sql_identifier, as that has changed representation in version 12 (Tomas Vondra)

  • Improve pg_upgrade's checks for the use of a data type that has changed representation, such as line (Tomas Vondra)

    The previous coding could be fooled by cases where the data type of interest underlies a stored column of a domain or composite type.

  • In pg_rewind with the --dry-run option, avoid updating pg_control (Alexey Kondratov)

    This could lead to failures in subsequent pg_rewind attempts.

  • Fix failure in pg_waldump with the -s option, when a continuation WAL record ends exactly at a page boundary (Andrey Lepikhov)

  • In pg_waldump with the --bkp-details option, avoid emitting extra newlines for WAL records involving full-page writes (Andres Freund)

  • Fix small memory leak in pg_waldump (Andres Freund)

  • Put back pqsignal() as an exported libpq symbol (Tom Lane)

    This function was removed on the grounds that no clients should be using it, but that turns out to break usage of current libpq with very old versions of psql, and perhaps other applications.

  • Fix configure's test for presence of libperl so that it works on recent Red Hat releases (Tom Lane)

    Previously, it could fail if the user sets CFLAGS to -O0.

  • Ensure correct code generation for spinlocks on PowerPC (Noah Misch)

    The previous spinlock coding allowed the compiler to select register zero for use with an assembly instruction that does not accept that register, causing a build failure. We have seen only one long-ago report that matches this bug, but it could cause problems for people trying to build modified PostgreSQL code or use atypical compiler options.

  • On AIX, don't use the compiler option -qsrcmsg (Noah Misch)

    This avoids an internal compiler error with xlc v16.1.0, with little consequence other than changing the format of compiler error messages.

  • Fix MSVC build process to cope with spaces in the file path of OpenSSL (Andrew Dunstan)

• ⇑ Upgrade to 12.2 released on 2020-02-13 - docs

  • Add missing permissions checks for ALTER ... DEPENDS ON EXTENSION (Álvaro Herrera)

    Marking an object as dependent on an extension did not have any privilege check whatsoever. This oversight allowed any user to mark routines, triggers, materialized views, or indexes as droppable by anyone able to drop an extension. Require that the calling user own the specified object (and hence have privilege to drop it). (CVE-2020-1720)

  • Fix TRUNCATE ... CASCADE to ensure all relevant partitions are truncated (Jehan-Guillaume de Rorthais)

    If a partition of a partitioned table is truncated with the CASCADE option, and the partitioned table has a foreign-key reference from another table, that table must also be truncated. The need to check this was missed if the referencing table was itself partitioned, possibly allowing rows to survive that violate the foreign-key constraint.

    Hence, if you have foreign key constraints between partitioned tables, and you have done any partition-level TRUNCATE on the referenced table, you should check to see if any foreign key violations exist. The simplest way is to add a new instance of the foreign key constraint (and, once that succeeds, drop it or the original constraint). That may be prohibitive from a locking standpoint, however, in which case you might prefer to manually query for unmatched rows.

  • Fix failure to attach foreign key constraints to sub-partitions (Jehan-Guillaume de Rorthais)

    When adding a partition to a level below the first level of a multi-level partitioned table, foreign key constraints referencing the top partitioned table were not cloned to the new partition, leading to possible constraint violations later. Detaching and re-attaching the new partition is the cheapest way to fix this. However, if there are many partitions to be fixed, adding a new instance of the foreign key constraint might be preferable.

  • Fix possible crash during concurrent update on a partitioned table or inheritance tree (Tom Lane)

  • Ensure that row triggers on partitioned tables are correctly cloned to sub-partitions when appropriate (Álvaro Herrera)

    User-defined triggers (but not triggers for foreign key or deferred unique constraints) might be missed when creating or attaching a partition.

  • Fix logical replication subscriber code to execute per-column UPDATE triggers when appropriate (Peter Eisentraut)

  • Avoid failure in logical decoding when a large transaction must be spilled into many separate temporary files (Amit Khandekar)

  • Fix possible crash or data corruption when a logical replication subscriber processes a row update (Tom Lane, Tomas Vondra)

    This bug caused visible problems only if the subscriber's table contained columns that were not being copied from the publisher and had pass-by-reference data types.

  • Fix crash in logical replication subscriber after DDL changes on a subscribed relation (Jehan-Guillaume de Rorthais, Vignesh C)

  • Fix failure in logical replication publisher after a database crash and restart (Vignesh C)

  • Ensure that the effect of pg_replication_slot_advance() on a physical replication slot will persist across restarts (Alexey Kondratov, Michael Paquier)

  • Improve efficiency of logical replication with REPLICA IDENTITY FULL (Konstantin Knizhnik)

    When searching for an existing tuple during an update or delete operation, return the first matching tuple not the last one.

  • Fix base backup to handle database OIDs larger than INT32_MAX (Peter Eisentraut)

  • Ensure parallel plans are always shut down at the correct time (Kyotaro Horiguchi)

    This oversight is known to result in “temporary file leak” warnings from multi-batch parallel hash joins.

  • Prevent premature shutdown of a Gather or GatherMerge plan node that is underneath a Limit node (Amit Kapila)

    This avoids failure if such a plan node needs to be scanned more than once, as for instance if it is on the inside of a nestloop.

  • Improve efficiency of parallel hash join on CPUs with many cores (Gang Deng, Thomas Munro)

  • Avoid crash in parallel CREATE INDEX when there are no free dynamic shared memory slots (Thomas Munro)

    Fall back to a non-parallel index build, instead.

  • Avoid memory leak when there are no free dynamic shared memory slots (Thomas Munro)

  • Ignore the CONCURRENTLY option when performing an index creation, drop, or rebuild on a temporary table (Michael Paquier, Heikki Linnakangas, Andres Freund)

    This avoids strange failures if the temporary table has an ON COMMIT action. There is no benefit in using CONCURRENTLY for a temporary table anyway, since other sessions cannot access the table, making the extra processing pointless.

  • Fix possible failure when resetting expression indexes on temporary tables that are marked ON COMMIT DELETE ROWS (Tom Lane)

  • Fix possible crash in BRIN index operations with box, range and inet data types (Heikki Linnakangas)

  • Fix crash during recursive page split in GiST index build (Heikki Linnakangas)

  • Fix handling of deleted pages in GIN indexes (Alexander Korotkov)

    Avoid possible deadlocks, incorrect updates of a deleted page's state, and failure to traverse through a recently-deleted page.

  • Fix possible crash with a SubPlan (sub-SELECT) within a multi-row VALUES list (Tom Lane)

  • Fix failure in ALTER TABLE when a column referenced in a GENERATED expression has been added or changed in type earlier in the same ALTER command (Tom Lane)

  • Fix failure to insert default values for “missing” attributes during tuple conversion (Vik Fearing, Andrew Gierth)

    This could result in values incorrectly reading as NULL, when they come from columns that had been added by ALTER TABLE ADD COLUMN with a constant default.

  • Fix unlikely panic in the checkpointer process, caused by opening relation segments that might already have been removed (Thomas Munro)

  • Fix crash after FileClose() failure (Noah Misch)

    This issue could only be observed with data_sync_retry enabled, since otherwise FileClose() failure would be reported as a PANIC.

  • Fix handling of multiple AFTER ROW triggers on a foreign table (Etsuro Fujita)

  • Fix unlikely crash with pass-by-reference aggregate transition states (Andres Freund, Teodor Sigaev)

  • Improve error reporting in to_date() and to_timestamp() (Tom Lane, Álvaro Herrera)

    Reports about incorrect month or day names in input strings could truncate the input in the middle of a multi-byte character, leading to an improperly encoded error message that could cause follow-on failures. Truncate at the next whitespace instead.

  • Fix off-by-one result for EXTRACT(ISOYEAR FROM timestamp) for BC dates (Tom Lane)

  • Ensure that the <> operator for type char reports indeterminate-collation errors as such, rather than as “cache lookup failed for collation 0” (Tom Lane)

  • Avoid treating TID scans as sequential scans (Tatsuhito Kasahara)

    A refactoring oversight caused TID scans (selection by CTID) to be counted as sequential scans in the statistics views, and to take whole-table predicate locks as sequential scans do. The latter behavior could cause unnecessary serialization errors in serializable transaction mode.

  • Avoid stack overflow in information_schema views when a self-referential view exists in the system catalogs (Tom Lane)

    A self-referential view can't work; it will always result in infinite recursion. We handled that situation correctly when trying to execute the view, but not when inquiring whether it is automatically updatable.

  • Ensure that walsender processes always show NULL for transaction start time in pg_stat_activity (Álvaro Herrera)

    Previously, the xact_start column would sometimes show the process start time.

  • Improve performance of hash joins with very large inner relations (Thomas Munro)

  • Reduce spinlock contention when there are many active walsender processes (Pierre Ducroquet)

  • Fix placement of “Subplans Removed” field in EXPLAIN output (Daniel Gustafsson, Tom Lane)

    In non-text output formats, this field was emitted inside the “Plans” sub-group, resulting in syntactically invalid output. Attach it to the parent Append or MergeAppend plan node as intended. This causes the field to change position in text output format too: if there are any InitPlans attached to the same plan node, “Subplans Removed” will now appear before those.

  • Fix EXPLAIN's SETTINGS option to print as empty in non-text output formats (Tom Lane)

    In the non-text output formats, fields are supposed to appear when requested, even if they have empty or zero values.

  • Allow the planner to apply potentially-leaky tests to child-table statistics, if the user can read the corresponding column of the table that's actually named in the query (Dilip Kumar, Amit Langote)

    This change fixes a performance problem for partitioned tables that was created by the fix for CVE-2017-7484. That security fix disallowed applying leaky operators to statistics for columns that the current user doesn't have permission to read directly. However, it's somewhat common to grant permissions only on the parent partitioned table and not bother to do so on individual partitions. In such cases, the user can read the column via the parent, so there's no point in this security restriction; it only results in poorer planner estimates than necessary.

  • Fix planner errors induced by overly-aggressive collapsing of joins to single-row subqueries (Tom Lane)

    This mistake led to errors such as “failed to construct the join relation”.

  • Fix “no = operator for opfamily NNNN” planner error when trying to match a LIKE or regex pattern-match operator to a binary-compatible index opclass (Tom Lane)

  • Fix edge-case crashes and misestimations in selectivity calculations for the <@ and @> range operators (Michael Paquier, Andrey Borodin, Tom Lane)

  • Fix incorrect estimation for OR clauses when using most-common-value extended statistics (Tomas Vondra)

  • Ignore system columns when applying most-common-value extended statistics (Tomas Vondra)

    This prevents “negative bitmapset member not allowed” planner errors for affected queries.

  • Fix BRIN index logic to support hypothetical BRIN indexes (Julien Rouhaud, Heikki Linnakangas)

    Previously, if an “index adviser” extension tried to get the planner to produce a plan involving a hypothetical BRIN index, that would fail, because the BRIN cost estimation code would always try to physically access the index's metapage. Now it checks to see if the index is only hypothetical, and uses default assumptions about the index parameters if so.

  • Improve error reporting for attempts to use automatic updating of views with conditional INSTEAD rules (Dean Rasheed)

    This has never been supported, but previously the error was thrown only at execution time, so that it could be masked by planner errors.

  • Prevent a composite type from being included in itself indirectly via a range type (Tom Lane, Julien Rouhaud)

  • Disallow partition key expressions that return pseudo-types, such as record (Tom Lane)

  • Fix error reporting for index expressions of prohibited types (Amit Langote)

  • Fix dumping of views that contain only a VALUES list to handle cases where a view output column has been renamed (Tom Lane)

  • Ensure that data types and collations used in XMLTABLE constructs are accounted for when computing dependencies of a view or rule (Tom Lane)

    Previously it was possible to break a view using XMLTABLE by dropping a type, if the type was not otherwise referenced in the view. This fix does not correct the dependencies already recorded for existing views, only for newly-created ones.

  • Prevent unwanted downcasing and truncation of RADIUS authentication parameters (Marcos David)

    The pg_hba.conf parser mistakenly treated these fields as SQL identifiers, which in general they aren't.

  • Transmit incoming NOTIFY messages to the client before sending ReadyForQuery, rather than after (Tom Lane)

    This change ensures that, with libpq and other client libraries that act similarly to it, any notifications received during a transaction will be available by the time the client thinks the transaction is complete. This probably makes no difference in practical applications (which would need to cope with asynchronous notifications in any case); but it makes it easier to build test cases with reproducible behavior.

  • Fix bugs in handling of non-blocking I/O when using GSSAPI encryption (Tom Lane)

    These errors could result in dropping data (usually leading to subsequent wire-protocol-violation errors) or in a “livelock” situation where a sending process goes to sleep although not all its data has been sent. Moreover, libpq failed to keep separate encryption state for each connection, creating the possibility for failures in applications using multiple encrypted database connections.

  • Allow libpq to parse all GSS-related connection parameters even when the GSSAPI code hasn't been compiled in (Tom Lane)

    This makes the behavior similar to our SSL support, where it was long ago deemed to be a good idea to always accept all the related parameters, even if some are ignored or restricted due to lack of the feature in a particular build.

  • Fix incorrect handling of %b and %B format codes in ecpg's PGTYPEStimestamp_fmt_asc() function (Tomas Vondra)

    Due to an off-by-one error, these codes would print the wrong month name, or possibly crash.

  • Avoid crash after an out-of-memory failure in ecpglib (Tom Lane)

  • Fix parallel pg_dump/pg_restore to more gracefully handle failure to create worker processes (Tom Lane)

  • Prevent possible crash or lockup when attempting to terminate a parallel pg_dump/pg_restore run via a signal (Tom Lane)

  • In pg_upgrade, look inside arrays and ranges while searching for non-upgradable data types in tables (Tom Lane)

  • Apply more thorough syntax checking to createuser's --connection-limit option (Álvaro Herrera)

  • Cope with changes of the specific type referenced by a PL/pgSQL composite-type variable in more cases (Ashutosh Sharma, Tom Lane)

    Dropping and re-creating the composite type referenced by a PL/pgSQL variable could lead to “could not open relation with OID NNNN” errors.

  • Avoid crash in postgres_fdw when trying to send a command like UPDATE remote_tab SET (x,y) = (SELECT ...) to the remote server (Tom Lane)

  • In contrib/dict_int, reject maxlen settings less than one (Tomas Vondra)

    This prevents a possible crash with silly settings for that parameter.

  • Disallow NULL category values in contrib/tablefunc's crosstab() function (Joe Conway)

    This case never worked usefully, and it would crash on some platforms.

  • Fix configure's probe for OpenSSL's SSL_clear_options() function so that it works with OpenSSL versions before 1.1.0 (Michael Paquier, Daniel Gustafsson)

    This problem could lead to failure to set the SSL compression option as desired, when PostgreSQL is built against an old version of OpenSSL.

  • Mark some timeout and statistics-tracking GUC variables as PGDLLIMPORT, to allow extensions to access them on Windows (Pascal Legrand)

    This applies to idle_in_transaction_session_timeout, lock_timeout, statement_timeout, track_activities, track_counts, and track_functions.

  • Avoid memory leak in sanity checks for “slab” memory contexts (Tomas Vondra)

    This isn't an issue for production builds, since they wouldn't ordinarily have memory context checking enabled; but the leak could be quite severe in a debug build.

  • Fix multiple statistics entries reported by the LWLock statistics mechanism (Fujii Masao)

    The LWLock statistics code (which is not built by default; it requires compiling with -DLWLOCK_STATS) could report multiple entries for the same LWLock and backend process, as a result of faulty hashtable key creation.

  • Fix race condition that led to delayed delivery of interprocess signals on Windows (Amit Kapila)

    This caused visible timing oddities in NOTIFY, and perhaps other misbehavior.

  • Fix handling of a corner-case error result from Windows' ReadFile() function (Thomas Munro, Juan José Santamaría Flecha)

    So far as is known, this oversight just resulted in noisy log messages, not any actual query misbehavior.

  • On Windows, retry a few times after an ERROR_ACCESS_DENIED file access failure (Alexander Lakhin, Tom Lane)

    This helps cope with cases where a file open attempt fails because the targeted file is flagged for deletion but not yet actually gone. pg_ctl, for example, frequently failed with such an error when probing to see if the postmaster had shut down yet.

  • On Windows, work around sharing violations for the postmaster's log file when pg_ctl is used to start the postmaster very shortly after it's been stopped, for example by pg_ctl restart (Alexander Lakhin)

• ⇑ Upgrade to 12.3 released on 2020-05-14 - docs

  • Fix possible failure with GENERATED columns (David Rowley)

    If a GENERATED column's value is an exact copy of another column of the table (and it is a pass-by-reference data type), it was possible to crash or insert corrupted data into the table. While it would be rather pointless for a GENERATED expression to just duplicate another column, an expression using a function that sometimes returns its input unchanged could create the situation.

  • Handle inheritance of generated columns better (Peter Eisentraut)

    When a table column is inherited during CREATE TABLE ... INHERITS, disallow changing any generation properties when the parent column is already marked GENERATED; but allow a child column to be marked GENERATED when its parent is not.

  • Fix cross-column references in CREATE TABLE LIKE INCLUDING GENERATED (Peter Eisentraut)

    CREATE TABLE ... LIKE failed when trying to copy a GENERATED expression that references a physically-later column.

  • Propagate ALTER TABLE ... SET STORAGE to indexes (Peter Eisentraut)

    Non-expression index columns have always copied the attstorage property of their table column at creation. Update them when ALTER TABLE ... SET STORAGE is done, to maintain consistency.

  • Preserve the indisclustered setting of indexes rewritten by ALTER TABLE (Amit Langote, Justin Pryzby)

    Previously, ALTER TABLE lost track of which index had been used for CLUSTER.

  • Preserve the replica identity properties of indexes rewritten by ALTER TABLE (Quan Zongliang, Peter Eisentraut)

  • Preserve the indisclustered setting of indexes rebuilt by REINDEX CONCURRENTLY (Justin Pryzby)

  • Lock objects sooner during DROP OWNED BY (Álvaro Herrera)

    This avoids failures in race-condition cases where another session is deleting some of the same objects.

  • Fix error-case processing for CREATE ROLE ... IN ROLE (Andrew Gierth)

    Some error cases would be reported as “unexpected node type” or the like, instead of the intended message.

  • Ensure that when a partition is detached, any triggers cloned from its formerly-parent table are removed (Justin Pryzby)

  • Fix crash when COLLATE is applied to a non-collatable type in a partition bound expression (Dmitry Dolgov)

  • Ensure that unique indexes over partitioned tables match the equality semantics of the partitioning key (Guancheng Luo)

    This would only be an issue with index opclasses that have unusual notions of equality, but it's wrong in theory, so check.

  • Ensure that members of the pg_read_all_stats role can read all statistics views, as expected (Magnus Hagander)

    The functions underlying the pg_stat_progress_* views had not gotten this memo.

  • Repair performance regression in information_schema.triggers view (Tom Lane)

    This patch redefines that view so that an outer WHERE clause constraining the table name can be pushed down into the view, allowing its calculations to be done only for triggers belonging to the table of interest rather than all triggers in the database. In a database with many triggers this would make a significant speed difference for queries of that form. Since things worked that way before v11, this is a potential performance regression. Users who find this to be a problem can fix it by replacing the view definition (or, perhaps, just deleting and reinstalling the whole information_schema schema).

  • Repair performance regression in floating point overflow/underflow detection (Emre Hasegeli)

    Previous refactoring had resulted in isinf() being called extra times in some hot code paths.

  • Fix full text search to handle NOT above a phrase search correctly (Tom Lane)

    Queries such as !(foo<->bar) failed to find matching rows when implemented as a GiST or GIN index search.

  • Fix full text search for cases where a phrase search includes an item with both prefix matching and a weight restriction (Tom Lane)

  • Fix ts_headline() to make better headline selections when working with phrase queries (Tom Lane)

  • Fix bugs in gin_fuzzy_search_limit processing (Adé Heyward, Tom Lane)

    A small value of gin_fuzzy_search_limit could result in unexpected slowness due to unintentionally rescanning the same index page many times. Another code path failed to apply the intended filtering at all, possibly returning too many values.

  • Allow input of type circle to accept the format “(x,y),r” as the documentation says it does (David Zhang)

  • Make the get_bit() and set_bit() functions cope with bytea strings longer than 256MB (Movead Li)

    Since the bit number argument is only int4, it's impossible to use these functions to access bits beyond the first 256MB of a long bytea. We'll widen the argument to int8 in v13, but in the meantime, allow these functions to work on the initial substring of a long bytea.

  • Ignore file-not-found errors in pg_ls_waldir() and allied functions (Tom Lane)

    This prevents a race condition failure if a file is removed between when we see its directory entry and when we attempt to stat() it.

  • Avoid possibly leaking an open-file descriptor for a directory in pg_ls_dir(), pg_timezone_names(), pg_tablespace_databases(), and allied functions (Justin Pryzby)

  • Fix polymorphic-function type resolution to correctly infer the actual type of an anyarray output when given only an anyrange input (Tom Lane)

  • Fix server's connection-startup logic for case where a GSSAPI connection is rejected because support is not compiled in, and the client then tries SSL instead (Andrew Gierth)

    This led to a bogus “unsupported frontend protocol” failure.

  • Fix memory leakage during GSSAPI encryption (Tom Lane)

    Both the backend and libpq would leak memory equivalent to the total amount of data sent during the session, if GSSAPI encryption is in use.

  • Fix query-lifespan memory leak for a set-returning function used in a query's FROM clause (Andres Freund)

  • Avoid leakage of a hashed subplan's hash tables across multiple executions (Andreas Karlsson, Tom Lane)

    This mistake could result in severe memory bloat if a query re-executed a hashed subplan enough times.

  • Improve planner's handling of no-op domain coercions (Tom Lane)

    Fix some cases where a domain coercion that does nothing was not completely removed from expressions.

  • Avoid unlikely crash when REINDEX is terminated by a session-shutdown signal (Tom Lane)

  • Prevent printout of possibly-incorrect hash join table statistics in EXPLAIN (Konstantin Knizhnik, Tom Lane, Thomas Munro)

  • Fix reporting of elapsed time for heap truncation steps in VACUUM VERBOSE (Tatsuhito Kasahara)

  • Fix possible undercounting of deleted B-tree index pages in VACUUM VERBOSE output (Peter Geoghegan)

  • Fix wrong bookkeeping for oldest deleted page in a B-tree index (Peter Geoghegan)

    This could cause subtly wrong decisions about when VACUUM can skip an index cleanup scan; although it appears there may be no significant user-visible effects from that.

  • Ensure that TimelineHistoryRead and TimelineHistoryWrite wait states are reported in all code paths that read or write timeline history files (Masahiro Ikeda)

  • Avoid possibly showing “waiting” twice in a process's PS status (Masahiko Sawada)

  • Avoid race condition when ANALYZE replaces the catalog tuple for extended statistics data (Dean Rasheed)

  • Remove ill-considered skip of “redundant” anti-wraparound vacuums (Michael Paquier)

    This avoids a corner case where autovacuum could get into a loop of repeatedly trying and then skipping the same vacuum job.

  • Ensure INCLUDE'd columns are always removed from B-tree pivot tuples (Peter Geoghegan)

    This mistake wasted space in some rare cases, but was otherwise harmless.

  • Cope with invalid TOAST indexes that could be left over after a failed REINDEX CONCURRENTLY (Julien Rouhaud)

  • Ensure that valid index dependencies are left behind after a failed REINDEX CONCURRENTLY (Michael Paquier)

    Previously the old index could be left with no pg_depend links at all, so that for example it would not get dropped if the parent table is dropped.

  • Avoid failure if autovacuum tries to access a just-dropped temporary schema (Tom Lane)

    This hazard only arises if a superuser manually drops a temporary schema; which isn't normal practice, but should work.

  • Avoid premature recycling of WAL segments during crash recovery (Jehan-Guillaume de Rorthais)

    WAL segments that become ready to be archived during crash recovery were potentially recycled without being archived.

  • Avoid scanning irrelevant timelines during archive recovery (Kyotaro Horiguchi)

    This can eliminate many attempts to fetch non-existent WAL files from archive storage, which is helpful if archive access is slow.

  • Remove bogus “subtransaction logged without previous top-level txn record” error check in logical decoding (Arseny Sher, Amit Kapila)

    This condition is legitimately reachable in various scenarios, so remove the check.

  • Avoid possible failure after a replication slot copy, due to premature removal of WAL data (Masahiko Sawada, Arseny Sher)

  • Ensure that a replication slot's io_in_progress_lock is released in failure code paths (Pavan Deolasee)

    This could result in a walsender later becoming stuck waiting for the lock.

  • Ensure that generated columns are correctly handled during updates issued by logical replication (Peter Eisentraut)

  • Fix race conditions in synchronous standby management (Tom Lane)

    During a change in the synchronous_standby_names setting, there was a window in which wrong decisions could be made about whether it is OK to release transactions that are waiting for synchronous commit. Another hazard for similarly wrong decisions existed if a walsender process exited and was immediately replaced by another.

  • Add missing SQLSTATE values to a few error reports (Sawada Masahiko)

  • Fix PL/pgSQL to reliably refuse to execute an event trigger function as a plain function (Tom Lane)

  • Fix memory leak in libpq when using sslmode=verify-full (Roman Peshkurov)

    Certificate verification during connection startup could leak some memory. This would become an issue if a client process opened many database connections during its lifetime.

  • Fix ecpg to treat an argument of just “-” as meaning “read from stdin” on all platforms (Tom Lane)

  • Fix crash in psql when attempting to re-establish a failed connection (Michael Paquier)

  • Allow tab-completion of the filename argument to psql's \gx command (Vik Fearing)

  • Add pg_dump support for ALTER ... DEPENDS ON EXTENSION (Álvaro Herrera)

    pg_dump previously ignored dependencies added this way, causing them to be forgotten during dump/restore or pg_upgrade.

  • Fix pg_dump to dump comments on RLS policy objects (Tom Lane)

  • In pg_dump, postpone restore of event triggers till the end (Fabrízio de Royes Mello, Hamid Akhtar, Tom Lane)

    This minimizes the risk that an event trigger could interfere with the restoration of other objects.

  • Ensure that pg_basebackup generates valid tar files (Robert Haas)

    In some cases a partial block of zeroes would be added to the end of the file. While this seems to be harmless with common versions of tar, it's not OK per the POSIX file format spec.

  • Make pg_checksums skip tablespace subdirectories that belong to a different PostgreSQL major version (Michael Banck, Bernd Helmle)

    Such subdirectories don't really belong to our database cluster, and so must not be processed.

  • Ignore temporary copies of pg_internal.init in pg_checksums and related programs (Michael Paquier)

  • Fix quoting of --encoding, --lc-ctype and --lc-collate values in createdb utility (Michael Paquier)

  • contrib/lo's lo_manage() function crashed if called directly rather than as a trigger (Tom Lane)

  • In contrib/ltree, protect against overflow of ltree and lquery length fields (Nikita Glukhov)

  • Work around failure in contrib/pageinspect's bt_metap() function when an oldest_xact value exceeds 2^31-1 (Peter Geoghegan)

    Such XIDs will now be reported as negative integers, which isn't great but it beats throwing an error. v13 will widen the output argument to int8 to provide saner reporting.

  • Fix cache reference leak in contrib/sepgsql (Michael Luo)

  • On Windows, avoid premature creation of postmaster's log file during pg_ctl start (Alexander Lakhin)

    The previous coding could allow the file to be created with permissions that wouldn't allow the postmaster to write on it.

  • Avoid failures when dealing with Unix-style locale names on Windows (Juan José Santamaría Flecha)

  • On Windows, set console VT100 compatibility mode in programs that support PG_COLOR colorization (Juan José Santamaría Flecha)

    Without this, the colorization option doesn't actually work.

  • Stop requiring extra parentheses in ereport() calls (Andres Freund, Tom Lane)

  • Use pkg-config, if available, to locate libxml2 during configure (Hugh McMaster, Tom Lane, Peter Eisentraut)

    If pkg-config is not present or lacks knowledge of libxml2, we still query xml2-config as before.

    This change could break build processes that try to make PostgreSQL use a non-default version of libxml2 by putting that version's xml2-config into the PATH. Instead, set XML2_CONFIG to point to the non-default xml2-config. That method will work with either older or newer PostgreSQL releases.

  • Fix Makefile dependencies for libpq and ecpg (Dagfinn Ilmari Mannsåker)

  • In MSVC builds, cope with spaces in the path name for Python (Victor Wagner)

  • In MSVC builds, fix detection of Visual Studio version to work with more language settings (Andrew Dunstan)

  • In MSVC builds, use -Wno-deprecated with bison versions newer than 3.0, as non-Windows builds already do (Andrew Dunstan)

  • Update time zone data files to tzdata release 2020a for DST law changes in Morocco and the Canadian Yukon, plus historical corrections for Shanghai.

    The America/Godthab zone has been renamed to America/Nuuk to reflect current English usage; however, the old name remains available as a compatibility link.

    Also, update initdb's list of known Windows time zone names to include recent additions, improving the odds that it will correctly translate the system time zone setting on that platform.

• ⇑ Upgrade to 12.4 released on 2020-08-13 - docs

  • Set a secure search_path in logical replication walsenders and apply workers (Noah Misch)

    A malicious user of either the publisher or subscriber database could potentially cause execution of arbitrary SQL code by the role running replication, which is often a superuser. Some of the risks here are equivalent to those described in CVE-2018-1058, and are mitigated in this patch by ensuring that the replication sender and receiver execute with empty search_path settings. (As with CVE-2018-1058, that change might cause problems for under-qualified names used in replicated tables' DDL.) Other risks are inherent in replicating objects that belong to untrusted roles; the most we can do is document that there is a hazard to consider. (CVE-2020-14349)

  • Make contrib modules' installation scripts more secure (Tom Lane)

    Attacks similar to those described in CVE-2018-1058 could be carried out against an extension installation script, if the attacker can create objects in either the extension's target schema or the schema of some prerequisite extension. Since extensions often require superuser privilege to install, this can open a path to obtaining superuser privilege. To mitigate this risk, be more careful about the search_path used to run an installation script; disable check_function_bodies within the script; and fix catalog-adjustment queries used in some contrib modules to ensure they are secure. Also provide documentation to help third-party extension authors make their installation scripts secure. This is not a complete solution; extensions that depend on other extensions can still be at risk if installed carelessly. (CVE-2020-14350)

  • Fix edge cases in partition pruning (Etsuro Fujita, Dmitry Dolgov)

    When there are multiple partition key columns, generation of pruning tests could misbehave if some columns had no constraining WHERE clauses or multiple constraining clauses. This could lead to server crashes, incorrect query results, or assertion failures.

  • Fix construction of parameterized BitmapAnd and BitmapOr index scans on the inside of partition-wise nestloop joins (Tom Lane)

    A plan in which such a scan needed to use a value from the outside of the join would usually crash at execution.

  • Fix incorrect plan execution when a partitioned table is subject to both static and run-time partition pruning in the same query, and a new partition is added concurrently with the query (Amit Langote, Tom Lane)

  • In logical replication walsender, fix failure to send feedback messages after sending a keepalive message (Álvaro Herrera)

    This is a relatively minor problem when using built-in logical replication, because the built-in walreceiver will send a feedback reply (which clears the incorrect state) fairly frequently anyway. But with some other replication systems, such as pglogical, it causes significant performance issues.

  • Fix firing of column-specific UPDATE triggers in logical replication subscribers (Tom Lane)

    The code neglected to account for the possibility of column numbers being different between the publisher and subscriber tables, so that if those were indeed different, wrong decisions might be made about which triggers to fire.

  • Update oldest xmin and LSN values during pg_replication_slot_advance() (Michael Paquier)

    This function previously failed to do that, possibly preventing resource cleanup (such as removal of no-longer-needed WAL segments) after manual advancement of a replication slot.

  • Fix slow execution of ts_headline() (Tom Lane)

    The phrase-search fix added in our previous set of minor releases could cause ts_headline() to take unreasonable amounts of time for long documents; to make matters worse, the query was not cancellable within the troublesome loop.

  • Ensure the repeat() function can be interrupted by query cancel (Joe Conway)

  • Fix pg_current_logfile() to not include a carriage return (\r) in its result on Windows (Tom Lane)

  • Ensure that pg_read_file() and related functions read until EOF is reached (Joe Conway)

    Previously, if not given a specific data length to read, these functions would stop at whatever file length was reported by stat(). That's unhelpful for pipes and other sorts of virtual files.

  • Forbid numeric NaN values in jsonpath computations (Alexander Korotkov)

    Neither SQL nor JSON have the concept of NaN (not-a-number), but the jsonpath code attempted to allow such values anyway. This necessarily leads to nonstandard behavior, so it seems better to reject such values at the outset.

  • Handle single Inf or NaN inputs correctly in floating-point aggregates (Tom Lane)

    The affected aggregates are corr(), covar_pop(), regr_intercept(), regr_r2(), regr_slope(), regr_sxx(), regr_sxy(), regr_syy(), stddev_pop(), and var_pop(). The correct answer in such cases is NaN, but an algorithmic change introduced in PostgreSQL v12 had caused these aggregates to produce zero instead.

  • Fix mis-handling of NaN inputs during parallel aggregation on numeric-type columns (Tom Lane)

    If some partial aggregation workers found only NaNs while others found only non-NaNs, the results were combined incorrectly, possibly leading to the wrong overall result (i.e., not NaN when it should be).

  • Reject time-of-day values greater than 24 hours (Tom Lane)

    The intention of the datetime input code is to allow “24:00:00” or equivalently “23:59:60”, but no larger value. However, the range check was miscoded so that it would accept “23:59:60.nnn” with nonzero fractional-second nnn. In timestamp values this would result in wrapping into the first second of the next day. In time and timetz values, the stored value would actually be more than 24 hours, causing dump/reload failures and possibly other misbehavior.

  • Undo double-quoting of index names in EXPLAIN's non-text output formats (Tom Lane, Euler Taveira)

  • Fix EXPLAIN's accounting for resource usage, particularly buffer accesses, in parallel workers in a plan using Gather Merge nodes (Jehan-Guillaume de Rorthais)

  • Fix timing of constraint revalidation in ALTER TABLE (David Rowley)

    If ALTER TABLE needs to fully rewrite the table's contents (for example, due to change of a column's data type) and also needs to scan the table to re-validate foreign keys or CHECK constraints, it sometimes did things in the wrong order, leading to odd errors such as “could not read block 0 in file "base/nnnnn/nnnnn": read only 0 of 8192 bytes”.

  • Fix REINDEX CONCURRENTLY to preserve the index's replication identity flag (Michael Paquier)

    Previously, reindexing a table's replica identity index caused the setting to be lost, preventing old tuple values from being included in future logical-decoding output.

  • Work around incorrect not-null markings for pg_subscription.subslotname and pg_subscription_rel.srsublsn (Tom Lane)

    The bootstrap catalog data incorrectly marks these two catalog columns as always non-null. There's no easy way to correct that mistake in existing installations (though v13 and later will have the correct markings). The main place that depends on that marking being correct is JIT-enabled tuple deconstruction, so teach it to explicitly ignore the marking for these two columns. Also adjust some C code that accessed srsublsn without checking to see if it's null; a crash from that is improbable but perhaps not impossible.

  • Cope with LATERAL references in restriction clauses attached to an un-flattened sub-SELECT in the FROM clause (Tom Lane)

    This oversight could result in assertion failures or crashes at query execution.

  • Use the query-specified collation for operators invoked during selectivity estimation (Tom Lane)

    Previously, the collation of the underlying database column was used. But using the query's collation is arguably more correct. More importantly, now that we have nondeterministic collations, there are cases where an operator will fail outright if given a nondeterministic collation. We don't want planning to fail in cases where the query itself would work, so this means that we must use the query's collation when invoking operators for estimation purposes.

  • Avoid believing that a never-analyzed foreign table has zero tuples (Tom Lane)

    This primarily affected the planner's estimate of the number of groups that would be obtained by GROUP BY.

  • Remove bogus warning about “leftover placeholder tuple” in BRIN index de-summarization (Álvaro Herrera)

    The case can occur legitimately after a cancelled vacuum, so warning about it is overly noisy.

  • Fix selection of tablespaces for “shared fileset” temporary files (Magnus Hagander, Tom Lane)

    If temp_tablespaces is empty or explicitly names the database's primary tablespace, such files got placed into the pg_default tablespace rather than the database's primary tablespace as expected.

  • Fix corner-case error in masking of SP-GiST index pages during WAL consistency checking (Alexander Korotkov)

    This could cause false failure reports when wal_consistency_checking is enabled.

  • Improve error handling in the server's buffile module (Thomas Munro)

    Fix some cases where I/O errors were indistinguishable from reaching EOF, or were not reported at all. Also add details such as block numbers and byte counts where appropriate.

  • Fix conflict-checking anomalies in SERIALIZABLE isolation mode (Peter Geoghegan)

    If a concurrently-inserted tuple was updated by a different concurrent transaction, and neither tuple version was visible to the current transaction's snapshot, serialization conflict checking could draw the wrong conclusions about whether the tuple was relevant to the results of the current transaction. This could allow a serializable transaction to commit when it should have failed with a serialization error.

  • Avoid repeated marking of dead btree index entries as dead (Masahiko Sawada)

    While functionally harmless, this led to useless WAL traffic when checksums are enabled or wal_log_hints is on.

  • Fix checkpointer process to discard file sync requests when fsync is off (Heikki Linnakangas)

    Such requests are treated as no-ops if fsync is off, but we forgot to remove them from the checkpointer's table of pending actions. This would lead to bloat of that table, as well as possible assertion failures if fsync is later re-enabled.

  • Avoid trouble during cleanup of a non-exclusive backup when JIT compilation has been activated during the backup (Robert Haas)

  • Fix failure of some code paths to acquire the correct lock before modifying pg_control (Nathan Bossart, Fujii Masao)

    This oversight could allow pg_control to be written out with an inconsistent checksum, possibly causing trouble later, including inability to restart the database if it crashed before the next pg_control update.

  • Fix errors in currtid() and currtid2() (Michael Paquier)

    These functions (which are undocumented and used only by ancient versions of the ODBC driver) contained coding errors that could result in crashes, or in confusing error messages such as “could not open file” when applied to a relation having no storage.

  • Avoid calling elog() or palloc() while holding a spinlock (Michael Paquier, Tom Lane)

    Logic associated with replication slots had several violations of this coding rule. While the odds of trouble are quite low, an error in the called function would lead to a stuck spinlock.

  • Fix assertion in logical replication subscriber to allow use of REPLICA IDENTITY FULL (Euler Taveira)

    This was just an incorrect assertion, so it has no impact on standard production builds.

  • Ensure that libpq continues to try to read from the database connection socket after a write failure (Tom Lane)

    This is important not only to ensure that we collect any final error message from a dying server process, but because we do not consider the connection lost until we see a read failure. This oversight allowed libpq to continue trying to send COPY data indefinitely after a mid-transfer loss of connection, rather than reporting failure to the application.

  • Fix bugs in libpq's management of GSS encryption state (Tom Lane)

    A connection using GSS encryption could freeze up when attempting to reset it after a server restart, or when moving on to the next one of a list of candidate servers.

  • Fix ecpg crash with bytea and cursor variables (Jehan-Guillaume de Rorthais)

  • Report out-of-disk-space errors properly in pg_dump and pg_basebackup (Justin Pryzby, Tom Lane, Álvaro Herrera)

    Some code paths could produce silly reports like “could not write file: Success”.

  • Make pg_restore cope with data-offset-less custom-format archive files when it needs to restore data items out of order (David Gilman, Tom Lane)

    pg_dump will produce such files if it cannot seek its output (for example, if the output is piped to something). This fix primarily improves the ability to do a parallel restore from such a file.

  • Fix parallel restore of tables having both table-level privileges and per-column privileges (Tom Lane)

    The table-level privilege grants have to be applied first, but a parallel restore did not reliably order them that way; this could lead to “tuple concurrently updated” errors, or to disappearance of some per-column privilege grants. The fix for this is to include dependency links between such entries in the archive file, meaning that a new dump has to be taken with a corrected pg_dump to ensure that the problem will not recur.

  • Ensure that pg_upgrade runs with vacuum_defer_cleanup_age set to zero in the target cluster (Bruce Momjian)

    If the target cluster's configuration has been modified to set vacuum_defer_cleanup_age to a nonzero value, that prevented freezing of the system catalogs from working properly, which caused the upgrade to fail in confusing ways. Ensure that any such setting is overridden for the duration of the upgrade.

  • Fix pg_recvlogical to drain pending messages before exiting (Noah Misch)

    Without this, the replication sender might detect a send failure and exit without making the expected final update to the replication slot's LSN position. That led to re-transmitting data after the next connection. It was also possible to miss error messages sent after the last data that pg_recvlogical wants to consume.

  • Fix pg_rewind's handling of just-deleted files in the source data directory (Justin Pryzby, Michael Paquier)

    When working with an on-line source database, concurrent file deletions are possible, but pg_rewind would get confused if deletion happened between seeing a file's directory entry and examining it with stat().

  • Make pg_test_fsync use binary I/O mode on Windows (Michael Paquier)

    Previously it wrote the test file in text mode, which is not an accurate reflection of PostgreSQL's actual usage.

  • Fix contrib/amcheck to not complain about deleted index pages that are empty (Alexander Korotkov)

    This state of affairs is normal during WAL replay.

  • Fix failure to initialize local state correctly in contrib/dblink (Joe Conway)

    With the right combination of circumstances, this could lead to dblink_close() issuing an unexpected remote COMMIT.

  • Fix contrib/pgcrypto's misuse of deflate() (Tom Lane)

    The pgp_sym_encrypt functions could produce incorrect compressed data due to mishandling of zlib's API requirements. We have no reports of this error manifesting with stock zlib, but it can be seen when using IBM's zlibNX implementation.

  • Fix corner case in decompression logic in contrib/pgcrypto's pgp_sym_decrypt functions (Kyotaro Horiguchi, Michael Paquier)

    A compressed stream can validly end with an empty packet, but the decompressor failed to handle this and would complain about corrupt data.

  • Support building our NLS code with Microsoft Visual Studio 2015 or later (Juan José Santamaría Flecha, Davinder Singh, Amit Kapila)

  • Avoid possible failure of our MSVC install script when there is a file named configure several levels above the source code tree (Arnold Müller)

    This could confuse some logic that looked for configure to identify the top level of the source tree.

• ⇑ Upgrade to 12.5 released on 2020-11-12 - docs

  • Block DECLARE CURSOR ... WITH HOLD and firing of deferred triggers within index expressions and materialized view queries (Noah Misch)

    This is essentially a leak in the “security restricted operation” sandbox mechanism. An attacker having permission to create non-temporary SQL objects could parlay this leak to execute arbitrary SQL code as a superuser.

    The PostgreSQL Project thanks Etienne Stalmans for reporting this problem. (CVE-2020-25695)

  • Fix usage of complex connection-string parameters in pg_dump, pg_restore, clusterdb, reindexdb, and vacuumdb (Tom Lane)

    The -d parameter of pg_dump and pg_restore, or the --maintenance-db parameter of the other programs mentioned, can be a “connection string” containing multiple connection parameters rather than just a database name. In cases where these programs need to initiate additional connections, such as parallel processing or processing of multiple databases, the connection string was forgotten and just the basic connection parameters (database name, host, port, and username) were used for the additional connections. This could lead to connection failures if the connection string included any other essential information, such as non-default SSL or GSS parameters. Worse, the connection might succeed but not be encrypted as intended, or be vulnerable to man-in-the-middle attacks that the intended connection parameters would have prevented. (CVE-2020-25694)

  • When psql's \connect command re-uses connection parameters, ensure that all non-overridden parameters from a previous connection string are re-used (Tom Lane)

    This avoids cases where reconnection might fail due to omission of relevant parameters, such as non-default SSL or GSS options. Worse, the reconnection might succeed but not be encrypted as intended, or be vulnerable to man-in-the-middle attacks that the intended connection parameters would have prevented. This is largely the same problem as just cited for pg_dump et al, although psql's behavior is more complex since the user may intentionally override some connection parameters. (CVE-2020-25694)

  • Prevent psql's \gset command from modifying specially-treated variables (Noah Misch)

    \gset without a prefix would overwrite whatever variables the server told it to. Thus, a compromised server could set specially-treated variables such as PROMPT1, giving the ability to execute arbitrary shell code in the user's session.

    The PostgreSQL Project thanks Nick Cleaton for reporting this problem. (CVE-2020-25696)

  • Prevent possible data loss from concurrent truncations of SLRU logs (Noah Misch)

    This rare problem would manifest in later “apparent wraparound” or “could not access status of transaction” errors.

  • Ensure that SLRU directories are properly fsync'd during checkpoints (Thomas Munro)

    This prevents possible data loss in a subsequent operating system crash.

  • Fix ALTER ROLE for users with the BYPASSRLS attribute (Tom Lane, Stephen Frost)

    The BYPASSRLS attribute is only allowed to be changed by superusers, but other ALTER ROLE operations, such as password changes, should be allowed with only ordinary permission checks. The previous coding erroneously restricted all changes on such a role to superusers.

  • Ensure that ALTER TABLE ONLY ... ENABLE/DISABLE TRIGGER does not recurse to child tables (Álvaro Herrera)

    Previously the ONLY flag was ignored.

  • Avoid unnecessary recursion to partitions in ALTER TABLE SET NOT NULL, when the target column is already marked NOT NULL (Tom Lane)

    This avoids a potential deadlock in parallel pg_restore.

  • Fix handling of expressions in CREATE TABLE LIKE with inheritance (Tom Lane)

    If a CREATE TABLE command uses both LIKE and traditional inheritance, column references in CHECK constraints and expression indexes that came from a LIKE parent table tended to get mis-numbered, resulting in wrong answers and/or bizarre error messages. The same could happen in GENERATED expressions, in branches that have that feature.

  • Disallow DROP INDEX CONCURRENTLY on a partitioned table (Álvaro Herrera, Michael Paquier)

    This case failed anyway, but with a confusing error message.

  • Allow LOCK TABLE to succeed on a self-referential view (Tom Lane)

    It previously threw an error complaining about infinite recursion, but there seems no need to disallow the case.

  • Retain statistics about an index across REINDEX CONCURRENTLY (Michael Paquier, Fabrízio de Royes Mello)

    Non-concurrent reindexing has always preserved such statistics.

  • Fix incorrect progress reporting from REINDEX CONCURRENTLY (Matthias van de Meent, Michael Paquier)

  • Ensure that GENERATED columns are updated when the column(s) they depend on are updated via a rule or an updatable view (Tom Lane)

    This fix also takes care of possible failure to fire a column-specific trigger in such cases.

  • Recheck default partition constraints while routing an inserted or updated tuple to the correct partition (Amit Langote, Álvaro Herrera)

    This fixes race conditions when partitions are added concurrently with the insertion.

  • Fix failures with collation-dependent partition bound expressions (Tom Lane)

  • Support hashing of text arrays (Peter Eisentraut)

    Array hashing failed if the array element type is collatable. Notably, this prevented using hash partitioning with a text array column as partition key.

  • Fix off-by-one conversion of negative years to BC dates in to_date() and to_timestamp() (Dar Alathar-Yemen, Tom Lane)

    Also, arrange for the combination of a negative year and an explicit “BC” marker to cancel out and produce AD.

  • Ensure that standby servers will archive WAL timeline history files when archive_mode is set to always (Grigory Smolkin, Fujii Masao)

    This oversight could lead to failure of subsequent PITR recovery attempts.

  • Fix “cache lookup failed for relation 0” failures in logical replication workers (Tom Lane)

    The real-world impact is small, since the failure is unlikely, and if it does happen the worker would just exit and be restarted.

  • Prevent logical replication workers from sending redundant ping requests (Tom Lane)

  • During “smart” shutdown, don't terminate background processes until all client (foreground) sessions are done (Tom Lane)

    The previous behavior broke parallel query processing, since the postmaster would terminate parallel workers and refuse to launch any new ones. It also caused autovacuum to cease functioning, which could have dire long-term effects if the surviving client sessions make a lot of data changes.

  • Avoid recursive consumption of stack space while processing signals in the postmaster (Tom Lane)

    Heavy use of parallel processing has been observed to cause postmaster crashes due to too many concurrent signals requesting creation of a parallel worker process.

  • Avoid running atexit handlers when exiting due to SIGQUIT (Kyotaro Horiguchi, Tom Lane)

    Most server processes followed this practice already, but the archiver process was overlooked. Backends that were still waiting for a client startup packet got it wrong, too.

  • Avoid misoptimization of subquery qualifications that reference apparently-constant grouping columns (Tom Lane)

    A “constant” subquery output column isn't really constant if it is a grouping column that appears in only some of the grouping sets.

  • Fix possible crash when considering partition-wise joins during GEQO planning (Tom Lane)

  • Avoid failure when SQL function inlining changes the shape of a potentially-hashable subplan comparison expression (Tom Lane)

  • While building or re-building an index, tolerate the appearance of new HOT chains due to concurrent updates (Anastasia Lubennikova, Álvaro Herrera)

    This oversight could lead to “failed to find parent tuple for heap-only tuple” errors.

  • Fix failure of parallel B-tree index scans when the index condition is unsatisfiable (James Hunter)

  • Ensure that data is detoasted before being inserted into a BRIN index (Tomas Vondra)

    Index entries are not supposed to contain out-of-line TOAST pointers, but BRIN didn't get that memo. This could lead to errors like “missing chunk number 0 for toast value NNN”. (If you are faced with such an error from an existing index, REINDEX should be enough to fix it.)

  • Handle concurrent desummarization correctly during BRIN index scans (Alexander Lakhin, Álvaro Herrera)

    Previously, if a page range was desummarized at just the wrong time, an index scan might falsely raise an error indicating index corruption.

  • Fix rare “lost saved point in index” errors in scans of multicolumn GIN indexes (Tom Lane)

  • Fix buffered GiST index builds to work when the index has included columns (Pavel Borisov)

  • Fix unportable use of getnameinfo() in pg_hba_file_rules view (Tom Lane)

    On FreeBSD 11, and possibly other platforms, the view's address and netmask columns were always null due to this error.

  • Avoid crash if debug_query_string is NULL when starting a parallel worker (Noah Misch)

  • Fix use-after-free hazard when an event trigger monitors an ALTER TABLE operation (Jehan-Guillaume de Rorthais)

  • Avoid failures when a BEFORE ROW UPDATE trigger returns the “old” row of a table having dropped or “missing” columns (Amit Langote, Tom Lane)

    This method of suppressing an update could result in crashes, unexpected CHECK constraint failures, or incorrect RETURNING output, because “missing” columns would read as NULLs for those purposes. (A column is “missing” for this purpose if it was added by ALTER TABLE ADD COLUMN with a non-NULL, but constant, default value.) Dropped columns could cause trouble as well.

  • Fix incorrect error message about inconsistent moving-aggregate data types (Jeff Janes)

  • Avoid lockup when a parallel worker reports a very long error message (Vignesh C)

  • Avoid unnecessary failure when transferring very large payloads through shared memory queues (Markus Wanner)

  • Fix incorrect handling of template function attributes in JIT code generation (Andres Freund)

    This has been shown to cause crashes on s390x, and very possibly there are other cases on other platforms.

  • Fix relation cache memory leaks with RLS policies (Tom Lane)

  • Fix edge-case memory leak in index_get_partition() (Justin Pryzby)

  • Fix small memory leak when SIGHUP processing decides that a new GUC variable value cannot be applied without a restart (Tom Lane)

  • Fix memory leaks in PL/pgsql's CALL processing (Pavel Stehule, Tom Lane)

  • Make libpq support arbitrary-length lines in .pgpass files (Tom Lane)

    This is mostly useful to allow using very long security tokens as passwords.

  • In libpq for Windows, call WSAStartup() once per process and WSACleanup() not at all (Tom Lane, Alexander Lakhin)

    Previously, libpq invoked WSAStartup() at connection start and WSACleanup() at connection cleanup. However, it appears that calling WSACleanup() can interfere with other program operations; notably, we have observed rare failures to emit expected output to stdout. There appear to be no ill effects from omitting the call, so do that. (This also eliminates a performance issue from repeated DLL loads and unloads when a program performs a series of database connections.)

  • Fix ecpg library's per-thread initialization logic for Windows (Tom Lane, Alexander Lakhin)

    Multi-threaded ecpg applications could suffer rare misbehavior due to incorrect locking.

  • On Windows, make psql read the output of a backtick command in text mode, not binary mode (Tom Lane)

    This ensures proper handling of newlines.

  • Ensure that pg_dump collects per-column information about extension configuration tables (Fabrízio de Royes Mello, Tom Lane)

    Failure to do this led to crashes when specifying --inserts, or underspecified (though usually correct) COPY commands when using COPY to reload the tables' data.

  • Ensure that parallel pg_restore processes foreign keys referencing partitioned tables in the correct order (Álvaro Herrera)

    Previously, it might try to restore a foreign key constraint before the required indexes were all in place, leading to an error.

  • Make pg_upgrade check for pre-existence of tablespace directories in the target cluster (Bruce Momjian)

  • Fix potential memory leak in contrib/pgcrypto (Michael Paquier)

  • Add check for an unlikely failure case in contrib/pgcrypto (Daniel Gustafsson)

  • Fix recently-added timetz test case so it works when the USA is not observing daylight savings time (Tom Lane)

  • Update time zone data files to tzdata release 2020d for DST law changes in Fiji, Morocco, Palestine, the Canadian Yukon, Macquarie Island, and Casey Station (Antarctica); plus historical corrections for France, Hungary, Monaco, and Palestine.

  • Sync our copy of the timezone library with IANA tzcode release 2020d (Tom Lane)

    This absorbs upstream's change of zic's default output option from “fat” to “slim”. That's just cosmetic for our purposes, as we continue to select the “fat” mode in pre-v13 branches. This change also ensures that strftime() does not change errno unless it fails.

• ⇑ Upgrade to 12.6 released on 2021-02-11 - docs

  • Fix information leakage in constraint-violation error messages (Heikki Linnakangas)

    If an UPDATE command attempts to move a row to a different partition but finds that it violates some constraint on the new partition, and the columns in that partition are in different physical positions than in the parent table, the error message could reveal the contents of columns that the user does not have SELECT privilege on. (CVE-2021-3393)

  • Fix incorrect detection of concurrent page splits while inserting into a GiST index (Heikki Linnakangas)

    Concurrent insertions could lead to a corrupt index with entries placed in the wrong pages. It's recommended to reindex any GiST index that's been subject to concurrent insertions.

  • Fix CREATE INDEX CONCURRENTLY to wait for concurrent prepared transactions (Andrey Borodin)

    At the point where CREATE INDEX CONCURRENTLY waits for all concurrent transactions to complete so that it can see rows they inserted, it must also wait for all prepared transactions to complete, for the same reason. Its failure to do so meant that rows inserted by prepared transactions might be omitted from the new index, causing queries relying on the index to miss such rows. In installations that have enabled prepared transactions (max_prepared_transactions > 0), it's recommended to reindex any concurrently-built indexes in case this problem occurred when they were built.

  • Avoid crash when a CALL or DO statement that performs a transaction rollback is executed via extended query protocol (Thomas Munro, Tom Lane)

    In PostgreSQL 13, this case reliably caused a null-pointer dereference. In earlier versions the bug seems to have no visible symptoms, but it's not quite clear that it could never cause a problem.

  • Fix partition pruning logic to handle asymmetric hash partition sets (Tom Lane)

    If a hash-partitioned table has unequally-sized partitions (that is, varying modulus values), or it lacks partitions for some remainder values, then the planner's pruning logic could mistakenly conclude that some partitions don't need to be scanned, leading to failure to find rows that the query should find.

  • Avoid incorrect results when WHERE CURRENT OF is applied to a cursor whose plan contains a MergeAppend node (Tom Lane)

    This case is unsupported (in general, a cursor using ORDER BY is not guaranteed to be simply updatable); but the code previously did not reject it, and could silently give false matches.

  • Fix crash when WHERE CURRENT OF is applied to a cursor whose plan contains a custom scan node (David Geier)

  • Fix planner's mishandling of placeholders whose evaluation should be delayed by an outer join (Tom Lane)

    This occurs in particular with trivial subqueries containing lateral references to outer-join outputs. The mistake could result in a malformed plan. The known cases trigger a “failed to assign all NestLoopParams to plan nodes” error, but other symptoms may be possible.

  • Fix planner's handling of placeholders during removal of useless RESULT RTEs (Tom Lane)

    This oversight could lead to “no relation entry for relid N” planner errors.

  • Fix planner's handling of a placeholder that is computed at some join level and used only at that same level (Tom Lane)

    This oversight could lead to “failed to build any N-way joins” planner errors.

  • Be more careful about whether index AMs support mark/restore (Andrew Gierth)

    This prevents errors about missing support functions in rare edge cases.

  • Adjust settings to make it more difficult to run out of DSM slots during heavy usage of parallel queries (Thomas Munro)

  • Fix overestimate of the amount of shared memory needed for parallel queries (Takayuki Tsunakawa)

  • Fix ALTER DEFAULT PRIVILEGES to handle duplicated arguments safely (Michael Paquier)

    Duplicate role or schema names within the same command could lead to “tuple already updated by self” errors or unique-constraint violations.

  • Flush ACL-related caches when pg_authid changes (Noah Misch)

    This change ensures that permissions-related decisions will promptly reflect the results of ALTER ROLE ... [NO] INHERIT.

  • Prevent misprocessing of ambiguous CREATE TABLE LIKE clauses (Tom Lane)

    A LIKE clause is re-examined after initial creation of the new table, to handle importation of indexes and such. It was possible for this re-examination to find a different table of the same name, causing unexpected behavior; one example is where the new table is a temporary table of the same name as the LIKE target.

  • Rearrange order of operations in CREATE TABLE LIKE so that indexes are cloned before building foreign key constraints (Tom Lane)

    This fixes the case where a self-referential foreign key constraint declared in the outer CREATE TABLE depends on an index that's coming from the LIKE clause.

  • Disallow CREATE STATISTICS on system catalogs (Tomas Vondra)

  • Disallow converting an inheritance child table to a view (Tom Lane)

  • Ensure that disk space allocated for a dropped relation is released promptly at commit (Thomas Munro)

    Previously, if the dropped relation spanned multiple 1GB segments, only the first segment was truncated immediately. Other segments were simply unlinked, which doesn't authorize the kernel to release the storage so long as any other backends still have the files open.

  • Prevent dropping a tablespace that is referenced by a partitioned relation, but is not used for any actual storage (Álvaro Herrera)

    Previously this was allowed, but subsequent operations on the partitioned relation would fail.

  • Fix progress reporting for CLUSTER (Matthias van de Meent)

  • Fix handling of backslash-escaped multibyte characters in COPY FROM (Heikki Linnakangas)

    A backslash followed by a multibyte character was not handled correctly. In some client character encodings, this could lead to misinterpreting part of a multibyte character as a field separator or end-of-copy-data marker.

  • Avoid preallocating executor hash tables in EXPLAIN without ANALYZE (Alexey Bashtanov)

  • Fix recently-introduced race conditions in LISTEN/NOTIFY queue handling (Tom Lane)

    A newly-listening backend could attempt to read SLRU pages that were in process of being truncated, possibly causing an error.

    The queue tail pointer could become set to a value that's not equal to the queue position of any backend, resulting in effective disabling of the queue truncation logic. Continued use of NOTIFY then led to queue-fill warnings, and eventually to inability to send any more notifies until the server is restarted.

  • Allow the jsonb concatenation operator to handle all combinations of JSON data types (Tom Lane)

    We can concatenate two JSON objects or two JSON arrays. Handle other cases by wrapping non-array inputs in one-element arrays, then performing an array concatenation. Previously, some combinations of inputs followed this rule but others arbitrarily threw an error.

  • Fix use of uninitialized value while parsing a * quantifier in a BRE-mode regular expression (Tom Lane)

    This error could cause the quantifier to act non-greedy, that is behave like a *? quantifier would do in full regular expressions.

  • Fix numeric power() for the case where the exponent is exactly INT_MIN (-2147483648) (Dean Rasheed)

    Previously, a result with no significant digits was produced.

  • Fix integer-overflow cases in substring() functions (Tom Lane, Pavel Stehule)

    If the specified starting index and length overflow an integer when added together, substring() misbehaved, either throwing a bogus “negative substring length” error for a case that should succeed, or failing to complain that a negative length is negative (and instead returning the whole string, in most cases).

  • Prevent possible data loss from incorrect detection of the wraparound point of an SLRU log (Noah Misch)

    The wraparound point typically falls in the middle of a page, which must be rounded off to a page boundary, and that was not done correctly. No issue could arise unless an installation had gotten to within one page of SLRU overflow, which is unlikely in a properly-functioning system. If this did happen, it would manifest in later “apparent wraparound” or “could not access status of transaction” errors.

  • Fix memory leak in walsender processes while sending new snapshots for logical decoding (Amit Kapila)

  • Fix walsender to accept additional commands after terminating replication (Jeff Davis)

  • Ensure detection of deadlocks between hot standby backends and the startup (WAL-application) process (Fujii Masao)

    The startup process did not run the deadlock detection code, so that in situations where the startup process is last to join a circular wait situation, the deadlock might never be recognized.

  • Fix possible failure to detect recovery conflicts while deleting an index entry that references a HOT chain (Peter Geoghegan)

    The code failed to traverse the HOT chain and might thus compute a too-old XID horizon, which could lead to incorrect conflict processing in hot standby. The practical impact of this bug is limited; in most cases the correct XID horizon would be found anyway from nearby operations.

  • Ensure that a nonempty value of krb_server_keyfile always overrides any setting of KRB5_KTNAME in the server's environment (Tom Lane)

    Previously, which setting took precedence depended on whether the client requests GSS encryption.

  • In server log messages about failing to match connections to pg_hba.conf entries, include details about whether GSS encryption has been activated (Kyotaro Horiguchi, Tom Lane)

    This is relevant data if hostgssenc or hostnogssenc entries exist.

  • Fix assorted issues in server's support for GSS encryption (Tom Lane)

    Remove pointless restriction that only GSS authentication can be used on a GSS-encrypted connection. Add GSS encryption information to connection-authorized log messages. Include GSS-related space when computing the required size of shared memory (this omission could have caused problems with very high max_connections settings). Avoid possible infinite recursion when reporting an unrecoverable GSS encryption error.

  • Ensure that unserviced requests for background workers are cleaned up when the postmaster begins a “smart” or “fast” shutdown sequence (Tom Lane)

    Previously, there was a race condition whereby a child process that had requested a background worker just before shutdown could wait indefinitely, preventing shutdown from completing.

  • Fix portability problem in parsing of recovery_target_xid values (Michael Paquier)

    The target XID is potentially 64 bits wide, but it was parsed with strtoul(), causing misbehavior on platforms where long is 32 bits (such as Windows).

  • Avoid trying to use parallel index build in a standalone backend (Yulin Pei)

  • Allow index AMs to support included columns without necessarily supporting multiple key columns (Tom Lane)

  • Avoid assertion failure during parallel aggregation of an aggregate with a non-strict deserialization function (Andrew Gierth)

    No such aggregate functions exist in core PostgreSQL, but some extensions such as PostGIS provide some. The mistake is harmless anyway in a non-assert build.

  • Avoid assertion failure in pg_get_functiondef() when examining a function with a TRANSFORM option (Tom Lane)

  • Fix data structure misallocation in PL/pgSQL's CALL statement (Tom Lane)

    A CALL in a PL/pgSQL procedure, to another procedure that has OUT parameters, would fail if the called procedure did a COMMIT or ROLLBACK.

  • In libpq, do not skip trying SSL after GSS encryption (Tom Lane)

    If we successfully made a GSS-encrypted connection, but then failed during authentication, we would fall back to an unencrypted connection rather than next trying an SSL-encrypted connection. This could lead to unexpected connection failure, or to silently getting an unencrypted connection where an encrypted one is expected. Fortunately, GSS encryption could only succeed if both client and server hold valid tickets in the same Kerberos infrastructure. It seems unlikely for that to be true in an environment that requires SSL encryption instead.

  • In psql, re-allow including a password in a connection_string argument of a \connect command (Tom Lane)

    This used to work, but a recent bug fix caused the password to be ignored (resulting in prompting for a password).

  • In psql's \d commands, don't truncate the display of column default values (Tom Lane)

    Formerly, they were arbitrarily truncated at 128 characters.

  • Fix assorted bugs in psql's \help command (Kyotaro Horiguchi, Tom Lane)

    \help with two argument words failed to find a command description using only the first word, for example \help reset all should show the help for RESET but did not. Also, \help often failed to invoke the pager when it should. It also leaked memory.

  • Fix pg_dump's dumping of inherited generated columns (Peter Eisentraut)

    The previous behavior resulted in (harmless) errors during restore.

  • In pg_dump, ensure that the restore script runs ALTER PUBLICATION ADD TABLE commands as the owner of the publication, and similarly runs ALTER INDEX ATTACH PARTITION commands as the owner of the partitioned index (Tom Lane)

    Previously, these commands would be run by the role that started the restore script; which will usually work, but in corner cases that role might not have adequate permissions.

  • Fix pg_dump to handle WITH GRANT OPTION in an extension's initial privileges (Noah Misch)

    If an extension's script creates an object and grants privileges on it with grant option, then later the user revokes such privileges, pg_dump would generate incorrect SQL for reproducing the situation. (Few if any extensions do this today.)

  • In pg_rewind, ensure that all WAL is accounted for when rewinding a standby server (Ian Barwick, Heikki Linnakangas)

  • In pgbench, disallow a digit as the first character of a variable name (Fabien Coelho)

    This prevents trying to substitute variables into timestamp literal values, which may contain strings like 12:34.

  • Report the correct database name in connection failure error messages from some client programs (Álvaro Herrera)

    If the database name was defaulted rather than given on the command line, pg_dumpall, pgbench, oid2name, and vacuumlo would produce misleading error messages after a connection failure.

  • Fix memory leak in contrib/auto_explain (Japin Li)

    Memory consumed while producing the EXPLAIN output was not freed until the end of the current transaction (for a top-level statement) or the end of the surrounding statement (for a nested statement). This was particularly a problem with log_nested_statements enabled.

  • In contrib/postgres_fdw, avoid leaking open connections to remote servers when a user mapping or foreign server object is dropped (Bharath Rupireddy)

    Open connections that depend on a dropped user mapping or foreign server can no longer be referenced, but formerly they were kept around anyway for the duration of the local session.

  • In contrib/pgcrypto, check for error returns from OpenSSL's EVP functions (Michael Paquier)

    We do not really expect errors here, but this change silences warnings from static analysis tools.

  • Make contrib/pg_prewarm more robust when the cluster is shut down before prewarming is complete (Tom Lane)

    Previously, autoprewarm would rewrite its status file with only the block numbers that it had managed to load so far, thus perhaps largely disabling the prewarm functionality in the next startup. Instead, suppress status file updates until the initial loading pass is complete.

  • In contrib/pg_trgm's GiST index support, avoid crash in the rare case that picksplit is called on exactly two index items (Andrew Gierth, Alexander Korotkov)

  • Fix miscalculation of timeouts in contrib/pg_prewarm and contrib/postgres_fdw (Alexey Kondratov, Tom Lane)

    The main loop in contrib/pg_prewarm's autoprewarm parent process underestimated its desired sleep time by a factor of 1000, causing it to consume much more CPU than intended. When waiting for a result from a remote server, contrib/postgres_fdw overestimated the desired timeout by a factor of 1000 (though this error had been mitigated by imposing a clamp to 60 seconds).

    Both of these errors stemmed from incorrectly converting seconds-and-microseconds to milliseconds. Introduce a new API TimestampDifferenceMilliseconds() to make it easier to get this right in the future.

  • Improve configure's heuristics for selecting PG_SYSROOT on macOS (Tom Lane)

    The new method is more likely to produce desirable results when Xcode is newer than the underlying operating system. Choosing a sysroot that does not match the OS version may result in nonfunctional executables.

  • While building on macOS, specify -isysroot in link steps as well as compile steps (James Hilliard)

    This likewise improves the results when Xcode is out of sync with the operating system.

  • Fix JIT compilation to be compatible with LLVM 11 and LLVM 12 (Andres Freund)

  • Fix potential mishandling of references to boolean variables in JIT expression compilation (Andres Freund)

    No field reports attributable to this have been seen, but it seems likely that it could cause problems on some architectures.

  • Fix compile failure with ICU 68 and later (Tom Lane)

  • Avoid memcpy() with a NULL source pointer and zero count during partitioned index creation (Álvaro Herrera)

    While such a call is not known to cause problems in itself, some compilers assume that the arguments of memcpy() are never NULL, which could result in incorrect optimization of nearby code.

  • Update time zone data files to tzdata release 2021a for DST law changes in Russia (Volgograd zone) and South Sudan, plus historical corrections for Australia, Bahamas, Belize, Bermuda, Ghana, Israel, Kenya, Nigeria, Palestine, Seychelles, and Vanuatu.

    Notably, the Australia/Currie zone has been corrected to the point where it is identical to Australia/Hobart.

• ⇑ Upgrade to 12.7 released on 2021-05-13 - docs

  • Prevent integer overflows in array subscripting calculations (Tom Lane)

    The array code previously did not complain about cases where an array's lower bound plus length overflows an integer. This resulted in later entries in the array becoming inaccessible (since their subscripts could not be written as integers), but more importantly it confused subsequent assignment operations. This could lead to memory overwrites, with ensuing crashes or unwanted data modifications. (CVE-2021-32027)

  • Fix mishandling of “junk” columns in INSERT ... ON CONFLICT ... UPDATE target lists (Tom Lane)

    If the UPDATE list contains any multi-column sub-selects (which give rise to junk columns in addition to the results proper), the UPDATE path would end up storing tuples that include the values of the extra junk columns. That's fairly harmless in the short run, but if new columns are added to the table then the values would become accessible, possibly leading to malfunctions if they don't match the datatypes of the added columns.

    In addition, in versions supporting cross-partition updates, a cross-partition update triggered by such a case had the reverse problem: the junk columns were removed from the target list, typically causing an immediate crash due to malfunction of the multi-column sub-select mechanism. (CVE-2021-32028)

  • Fix possibly-incorrect computation of UPDATE ... RETURNING outputs for joined cross-partition updates (Amit Langote, Etsuro Fujita)

    If an UPDATE for a partitioned table caused a row to be moved to another partition with a physically different row type (for example, one with a different set of dropped columns), computation of RETURNING results for that row could produce errors or wrong answers. No error is observed unless the UPDATE involves other tables being joined to the target table. (CVE-2021-32029)

  • Fix adjustment of constraint deferrability properties in partitioned tables (Álvaro Herrera)

    When applied to a foreign-key constraint of a partitioned table, ALTER TABLE ... ALTER CONSTRAINT failed to adjust the DEFERRABLE and/or INITIALLY DEFERRED markings of the constraints and triggers of leaf partitions. This led to unexpected behavior of such constraints. After updating to this version, any misbehaving partitioned tables can be fixed by executing a new ALTER command to set the desired properties.

    This change also disallows applying such an ALTER directly to the constraints of leaf partitions. The only supported case is for the whole partitioning hierarchy to have identical constraint properties, so such ALTERs must be applied at the partition root.

  • When attaching a child table with ALTER TABLE ... INHERIT, insist that any generated columns in the parent be generated the same way in the child (Peter Eisentraut)

  • Forbid marking an identity column as nullable (Vik Fearing)

    GENERATED ALWAYS AS IDENTITY implies NOT NULL, so don't allow it to be combined with an explicit NULL specification.

  • Allow ALTER ROLE/DATABASE ... SET to set the role, session_authorization, and temp_buffers parameters (Tom Lane)

    Previously, over-eager validity checks might reject these commands, even if the values would have worked when used later. This created a command ordering hazard for dump/reload and upgrade scenarios.

  • Ensure that REINDEX CONCURRENTLY preserves any statistics target that's been set for the index (Michael Paquier)

  • Fix COMMIT AND CHAIN to work correctly when the current transaction has live savepoints (Fujii Masao)

  • Fix bug with coercing the result of a COLLATE expression to a non-collatable type (Tom Lane)

    This led to a parse tree in which the COLLATE appears to be applied to a non-collatable value. While that normally has no real impact (since COLLATE has no effect at runtime), it was possible to construct views that would be rejected during dump/reload.

  • Fix use-after-free bug in saving tuples for AFTER triggers (Amit Langote)

    This could cause crashes in some situations.

  • Disallow calling window functions and procedures via the “fast path” wire protocol message (Tom Lane)

    Only plain functions are supported here. While trying to call an aggregate function failed already, calling a window function would crash, and calling a procedure would work only if the procedure did no transaction control.

  • Extend pg_identify_object_as_address() to support event triggers (Joel Jacobson)

  • Fix to_char()'s handling of Roman-numeral month format codes with negative intervals (Julien Rouhaud)

    Previously, such cases would usually cause a crash.

  • Check that the argument of pg_import_system_collations() is a valid schema OID (Tom Lane)

  • Fix use of uninitialized value while parsing an \{m,n\} quantifier in a BRE-mode regular expression (Tom Lane)

    This error could cause the quantifier to act non-greedy, that is behave like an {m,n}? quantifier would do in full regular expressions.

  • Don't ignore system columns when estimating the number of groups using extended statistics (Tomas Vondra)

    This led to strange estimates for queries such as SELECT ... GROUP BY a, b, ctid.

  • Avoid divide-by-zero when estimating selectivity of a regular expression with a very long fixed prefix (Tom Lane)

    This typically led to a NaN selectivity value, causing assertion failures or strange planner behavior.

  • Fix access-off-the-end-of-the-table error in BRIN index bitmap scans (Tomas Vondra)

    If the page range size used by a BRIN index isn't a power of two, there were corner cases in which a bitmap scan could try to fetch pages past the actual end of the table, leading to “could not open file” errors.

  • Avoid incorrect timeline change while recovering uncommitted two-phase transactions from WAL (Soumyadeep Chakraborty, Jimmy Yih, Kevin Yeap)

    This error could lead to subsequent WAL records being written under the wrong timeline ID, leading to consistency problems, or even complete failure to be able to restart the server, later on.

  • Ensure that locks are released while shutting down a standby server's startup process (Fujii Masao)

    When a standby server is shut down while still in recovery, some locks might be left held. This causes assertion failures in debug builds; it's unclear whether any serious consequence could occur in production builds.

  • Fix crash when a logical replication worker does ALTER SUBSCRIPTION REFRESH (Peter Smith)

    The core code won't do this, but a replica trigger could.

  • Ensure we default to wal_sync_method = fdatasync on recent FreeBSD (Thomas Munro)

    FreeBSD 13 supports open_datasync, which would normally become the default choice. However, it's unclear whether that is actually an improvement for Postgres, so preserve the existing default for now.

  • Pass the correct trigger OID to object post-alter hooks during ALTER CONSTRAINT (Álvaro Herrera)

    When updating trigger properties during ALTER CONSTRAINT, the post-alter hook was told that we are updating a trigger, but the constraint's OID was passed instead of the trigger's.

  • Ensure we finish cleaning up when interrupted while detaching a DSM segment (Thomas Munro)

    This error could result in temporary files not being cleaned up promptly after a parallel query.

  • Fix memory leak while initializing server's SSL parameters (Michael Paquier)

    This is ordinarily insignificant, but if the postmaster is repeatedly sent SIGHUP signals, the leak can build up over time.

  • Fix assorted minor memory leaks in the server (Tom Lane, Andres Freund)

  • Fix failure when a PL/pgSQL DO block makes use of both composite-type variables and transaction control (Tom Lane)

    Previously, such cases led to errors about leaked tuple descriptors.

  • Prevent infinite loop in libpq if a ParameterDescription message with a corrupt length is received (Tom Lane)

  • When initdb prints instructions about how to start the server, make the path shown for pg_ctl use backslash separators on Windows (Nitin Jadhav)

  • Fix psql to restore the previous behavior of \connect service=something (Tom Lane)

    A previous bug fix caused environment variables (such as PGPORT) to override entries in the service file in this context. Restore the previous behavior, in which the priority is the other way around.

  • Fix psql's ON_ERROR_ROLLBACK feature to handle COMMIT AND CHAIN commands correctly (Arthur Nascimento)

    Previously, this case failed with “savepoint "pg_psql_temporary_savepoint" does not exist”.

  • Fix race condition in detection of file modification by psql's \e and related commands (Laurenz Albe)

    A very fast typist could fool the code's file-timestamp-based detection of whether the temporary edit file was changed.

  • Fix pg_dump's dumping of generated columns in partitioned tables (Peter Eisentraut)

    A fix introduced in the previous minor release should not be applied to partitioned tables, only traditionally-inherited tables.

  • Fix missed file version check in pg_restore (Tom Lane)

    When reading a custom-format archive from a non-seekable source, pg_restore neglected to check the archive version. If it was fed a newer archive version than it can support, it would fail messily later on.

  • Add some more checks to pg_upgrade for user tables containing non-upgradable data types (Tom Lane)

    Fix detection of some cases where a non-upgradable data type is embedded within a container type (such as an array or range). Also disallow upgrading when user tables contain columns of system-defined composite types, since those types' OIDs are not stable across versions.

  • Fix incorrect progress-reporting calculation in pg_checksums (Shinya Kato)

  • Fix pg_waldump to count XACT records correctly when generating per-record statistics (Kyotaro Horiguchi)

  • Fix contrib/amcheck to not complain about the tuple flags HEAP_XMAX_LOCK_ONLY and HEAP_KEYS_UPDATED both being set (Julien Rouhaud)

    This is a valid state after SELECT FOR UPDATE.

  • Adjust VPATH build rules to support recent Oracle Developer Studio compiler versions (Noah Misch)

  • Fix testing of PL/Python for Python 3 on Solaris (Noah Misch)

• ⇑ Upgrade to 12.8 released on 2021-08-12 - docs

  • Fix mis-planning of repeated application of a projection step (Tom Lane)

    The planner could create an incorrect plan in cases where two ProjectionPaths were stacked on top of each other. The only known way to trigger that situation involves parallel sort operations, but there may be other instances. The result would be crashes or incorrect query results. Disclosure of server memory contents is also possible. (CVE-2021-3677)

  • Disallow SSL renegotiation more completely (Michael Paquier)

    SSL renegotiation has been disabled for some time, but the server would still cooperate with a client-initiated renegotiation request. A maliciously crafted renegotiation request could result in a server crash (see OpenSSL issue CVE-2021-3449). Disable the feature altogether on OpenSSL versions that permit doing so, which are 1.1.0h and newer.

  • Restore the Portal-level snapshot after COMMIT or ROLLBACK within a procedure (Tom Lane)

    This change fixes cases where an attempt to fetch a toasted value immediately after COMMIT/ROLLBACK would fail with errors like “no known snapshots” or “missing chunk number 0 for toast value”.

    Some extensions may attempt to execute SQL code outside of any Portal. They are responsible for ensuring that an outer snapshot exists before doing so. Previously, not providing a snapshot might work or it might not; now it will consistently fail with “cannot execute SQL without an outer snapshot or portal”.

  • Avoid misbehavior when persisting the output of a cursor that's reading a non-stable query (Tom Lane)

    Previously, we'd always rewind and re-read the whole query result, possibly getting results different from the earlier execution, causing great confusion later. For a NO SCROLL cursor, we can fix this by only storing the not-yet-read portion of the query output, which is sufficient since a NO SCROLL cursor can't be backed up. Cursors with the SCROLL option remain at hazard, but that was already documented to be an unsafe option to use with a non-stable query. Make those documentation warnings stronger.

    Also force NO SCROLL mode for the implicit cursor used by a PL/pgSQL FOR-over-query loop, to avoid this type of problem when persisting such a cursor during an intra-procedure commit.

  • Reject SELECT ... GROUP BY GROUPING SETS (()) FOR UPDATE (Tom Lane)

    This should be disallowed, just as FOR UPDATE with a plain GROUP BY is disallowed, but the test for that failed to handle empty grouping sets correctly. The end result would be a null-pointer dereference in the executor.

  • Reject cases where a query in WITH rewrites to just NOTIFY (Tom Lane)

    Such cases previously crashed.

  • In numeric multiplication, round the result rather than failing if it would have more than 16383 digits after the decimal point (Dean Rasheed)

  • Fix corner-case errors and loss of precision when raising numeric values to very large powers (Dean Rasheed)

  • Fix division-by-zero failure in to_char() with EEEE format and a numeric input value less than 10^(-1001) (Dean Rasheed)

  • Fix pg_size_pretty(bigint) to round negative values consistently with the way it rounds positive ones (and consistently with the numeric version) (Dean Rasheed, David Rowley)

  • Make pg_filenode_relation(0, 0) return NULL rather than failing (Justin Pryzby)

  • Make ALTER EXTENSION lock the extension when adding or removing a member object (Tom Lane)

    The previous coding allowed ALTER EXTENSION ADD/DROP to occur concurrently with DROP EXTENSION, leading to a crash or corrupt catalog entries.

  • Fix ALTER SUBSCRIPTION to reject an empty slot name (Japin Li)

  • When cloning a partitioned table's triggers to a new partition, ensure that their enabled status is copied (Álvaro Herrera)

  • Avoid alias conflicts in queries generated for REFRESH MATERIALIZED VIEW CONCURRENTLY (Tom Lane, Bharath Rupireddy)

    This command failed on materialized views containing columns with certain names, notably mv and newdata.

  • Fix PREPARE TRANSACTION to check correctly for conflicting session-lifespan and transaction-lifespan locks (Tom Lane)

    A transaction cannot be prepared if it has both session-lifespan and transaction-lifespan locks on the same advisory-lock ID value. This restriction was not fully checked, which could lead to a PANIC during PREPARE TRANSACTION.

  • Fix misbehavior of DROP OWNED BY when the target role is listed more than once in an RLS policy (Tom Lane)

  • Skip unnecessary error tests when removing a role from an RLS policy during DROP OWNED BY (Tom Lane)

    Notably, this fixes some cases where it was necessary to be a superuser to use DROP OWNED BY.

  • Disallow whole-row variables in GENERATED expressions (Tom Lane)

    Use of a whole-row variable clearly violates the rule that a generated column cannot depend on itself, so such cases have no well-defined behavior. The actual behavior frequently included a crash.

  • Fix usage of tableoid in GENERATED expressions (Tom Lane)

    Some code paths failed to provide a valid value for this system column while evaluating a GENERATED expression.

  • Don't store a “fast default” when adding a column to a foreign table (Andrew Dunstan)

    The fast default is useless since no local heap storage exists for such a table, but it confused subsequent operations. In addition to suppressing creation of such catalog entries in ALTER TABLE commands, adjust the downstream code to cope when one is incorrectly present.

  • Allow index state flags to be updated transactionally (Michael Paquier, Andrey Lepikhov)

    This avoids failures when dealing with index predicates that aren't really immutable. While that's not considered a supported case, the original reason for using a non-transactional update here is long gone, so we may as well change it.

  • Avoid corrupting the plan cache entry when CREATE DOMAIN or ALTER DOMAIN appears in a cached plan (Tom Lane)

  • Make walsenders show their latest replication commands in pg_stat_activity (Tom Lane)

    Previously, a walsender would show its latest SQL command, which was confusing if it's now doing some replication operation instead. Now we show replication-protocol commands on the same footing as SQL commands.

  • Make pg_settings.pending_restart show as true when the pertinent entry in postgresql.conf has been removed (Álvaro Herrera)

    pending_restart correctly showed the case where an entry that cannot be changed without a postmaster restart has been modified, but not where the entry had been removed altogether.

  • Fix mis-planning of queries involving regular tables that are inheritance children of foreign tables (Amit Langote)

    SELECT FOR UPDATE and related commands would fail with assertion failures or “could not find junk column” errors in such cases.

  • Fix corner-case failure of a new standby to follow a new primary (Dilip Kumar, Robert Haas)

    Under a narrow combination of conditions, the standby could wind up trying to follow the wrong WAL timeline.

  • Update minimum recovery point when WAL replay of a transaction abort record causes file truncation (Fujii Masao)

    File truncation is irreversible, so it's no longer safe to stop recovery at a point earlier than that record. The corresponding case for transaction commit was fixed years ago, but this one was overlooked.

  • In walreceivers, avoid attempting catalog lookups after an error (Masahiko Sawada, Bharath Rupireddy)

  • Ensure that a standby server's startup process will respond to a shutdown signal promptly while waiting for WAL to arrive (Fujii Masao, Soumyadeep Chakraborty)

  • Correctly clear shared state after failing to become a member of a transaction commit group (Amit Kapila)

    Given the right timing, this could cause an assertion failure when some later session re-uses the same PGPROC object.

  • Add locking to avoid reading incorrect relmapper data in the face of a concurrent write from another process (Heikki Linnakangas)

  • Improve progress reporting for the sort phase of a parallel btree index build (Matthias van de Meent)

  • Improve checks for violations of replication protocol (Tom Lane)

    Logical replication workers frequently used Asserts to check for cases that could be triggered by invalid or out-of-order replication commands. This seems unwise, so promote these tests to regular error checks.

  • Fix deadlock when multiple logical replication workers try to truncate the same table (Peter Smith, Haiying Tang)

  • Fix error cases and memory leaks in logical decoding of speculative insertions (Dilip Kumar)

  • Avoid leaving an invalid record-type hash table entry behind after an error (Sait Talha Nisanci)

    This could lead to later crashes or memory leakage.

  • Fix plan cache reference leaks in some error cases in CREATE TABLE ... AS EXECUTE (Tom Lane)

  • Fix race condition in code for sharing tuple descriptors across parallel workers (Thomas Munro)

    Given the right timing, a crash could result.

  • Fix possible race condition when releasing BackgroundWorkerSlots (Tom Lane)

    It's likely that this doesn't fix any observable bug on Intel hardware, but machines with weaker memory ordering rules could have problems.

  • Fix latent crash in sorting code (Ronan Dunklau)

    One code path could attempt to free a null pointer. The case appears unreachable in the core server's use of sorting, but perhaps it could be triggered by extensions.

  • Prevent infinite loops in SP-GiST index insertion (Tom Lane)

    In the event that INCLUDE columns take up enough space to prevent a leaf index tuple from ever fitting on a page, the text_ops operator class would get into an infinite loop vainly trying to make the tuple fit. While pre-v11 versions don't have INCLUDE columns, back-patch this anti-looping fix to them anyway, as it seems like a good defense against bugs in operator classes.

  • Ensure that SP-GiST index insertion can be terminated by a query cancel request (Tom Lane, Álvaro Herrera)

  • Fix uninitialized-variable bug that could cause PL/pgSQL to act as though an INTO clause specified STRICT, even though it didn't (Tom Lane)

  • Don't abort the process for an out-of-memory failure in libpq's printing functions (Tom Lane)

  • In ecpg, allow the numeric value INT_MIN (usually -2147483648) to be converted to integer (John Naylor)

  • In psql and other client programs, avoid overrunning the ends of strings when dealing with invalidly-encoded data (Tom Lane)

    An incorrectly-encoded multibyte character near the end of a string could cause various processing loops to run past the string's terminating NUL, with results ranging from no detectable issue to a program crash, depending on what happens to be in the following memory. This is reminiscent of CVE-2006-2313, although these particular cases do not appear to have interesting security consequences.

  • Fix pg_dump to correctly handle triggers on partitioned tables whose enabled status is different from their parent triggers' status (Justin Pryzby, Álvaro Herrera)

  • Avoid “invalid creation date in header” warnings observed when running pg_restore on an archive file created in a different time zone (Tom Lane)

  • Make pg_upgrade carry forward the old installation's oldestXID value (Bertrand Drouvot)

    Previously, the new installation's oldestXID was set to a value old enough to (usually) force immediate anti-wraparound autovacuuming. That's not desirable from a performance standpoint; what's worse, installations using large values of autovacuum_freeze_max_age could suffer unwanted forced shutdowns soon after an upgrade.

  • Extend pg_upgrade to detect and warn about extensions that should be upgraded (Bruce Momjian)

    A script file is now produced containing the ALTER EXTENSION UPDATE commands needed to bring extensions up to the versions that are considered default in the new installation.

  • Avoid problems when switching pg_receivewal between compressed and non-compressed WAL storage (Michael Paquier)

  • Fix contrib/postgres_fdw to work usefully with generated columns (Etsuro Fujita)

    postgres_fdw will now behave reasonably with generated columns, so long as a generated column in a foreign table represents a generated column in the remote table. IMPORT FOREIGN SCHEMA will now import generated columns that way by default.

  • In contrib/postgres_fdw, avoid attempting catalog lookups after an error (Tom Lane)

    While this usually worked, it's not very safe since the error might have been one that made catalog access nonfunctional. A side effect of the fix is that messages about data conversion errors will now mention the query's table and column aliases (if used) rather than the true underlying name of a foreign table or column.

  • Improve the isolation-test infrastructure (Tom Lane, Michael Paquier)

    Allow isolation test steps to be annotated to show the expected completion order. This allows getting stable results from otherwise-racy test cases, without the long delays that we previously used (not entirely successfully) to fend off race conditions. Allow non-quoted identifiers as isolation test session/step names (formerly, all such names had to be double-quoted). Detect and warn about unused steps in isolation tests. Improve display of query results in isolation tests. Remove isolationtester's “dry-run” mode. Remove memory leaks in isolationtester itself.

  • Reduce overhead of cache-clobber testing (Tom Lane)

  • Fix PL/Python's regression tests to pass with Python 3.10 (Honza Horak)

  • Make printf("%s", NULL) print (null) instead of crashing (Tom Lane)

    This should improve server robustness in corner cases, and it syncs our printf implementation with common libraries.

  • Fix incorrect log message when point-in-time recovery stops at a ROLLBACK PREPARED record (Simon Riggs)

  • Improve ALTER TABLE's messages for wrong-relation-kind errors (Kyotaro Horiguchi)

  • Clarify error messages referring to “non-negative” values (Bharath Rupireddy)

  • Fix configure to work with OpenLDAP 2.5, which no longer has a separate libldap_r library (Adrian Ho, Tom Lane)

    If there is no libldap_r library, we now silently assume that libldap is thread-safe.

  • Add new make targets world-bin and install-world-bin (Andrew Dunstan)

    These are the same as world and install-world respectively, except that they do not build or install the documentation.

  • Fix make rule for TAP tests (prove_installcheck) to work in PGXS usage (Andrew Dunstan)

  • Adjust JIT code to prepare for forthcoming LLVM API change (Thomas Munro, Andres Freund)

    LLVM 13 has made an incompatible API change that will cause crashing of our previous JIT compiler.

  • Avoid assuming that strings returned by GSSAPI libraries are null-terminated (Tom Lane)

    The GSSAPI spec provides for a string pointer and length. It seems that in practice the next byte after the string is usually zero, so that our previous coding didn't actually fail; but we do have a report of AddressSanitizer complaints.

  • Enable building with GSSAPI on MSVC (Michael Paquier)

    Fix various incompatibilities with modern Kerberos builds.

  • In MSVC builds, include --with-pgport in the set of configure options reported by pg_config, if it had been specified (Andrew Dunstan)

• ⇑ Upgrade to 12.9 released on 2021-11-11 - docs

  • Make the server reject extraneous data after an SSL or GSS encryption handshake (Tom Lane)

    A man-in-the-middle with the ability to inject data into the TCP connection could stuff some cleartext data into the start of a supposedly encryption-protected database session. This could be abused to send faked SQL commands to the server, although that would only work if the server did not demand any authentication data. (However, a server relying on SSL certificate authentication might well not do so.)

    The PostgreSQL Project thanks Jacob Champion for reporting this problem. (CVE-2021-23214)

  • Make libpq reject extraneous data after an SSL or GSS encryption handshake (Tom Lane)

    A man-in-the-middle with the ability to inject data into the TCP connection could stuff some cleartext data into the start of a supposedly encryption-protected database session. This could probably be abused to inject faked responses to the client's first few queries, although other details of libpq's behavior make that harder than it sounds. A different line of attack is to exfiltrate the client's password, or other sensitive data that might be sent early in the session. That has been shown to be possible with a server vulnerable to CVE-2021-23214.

    The PostgreSQL Project thanks Jacob Champion for reporting this problem. (CVE-2021-23222)

  • Fix physical replication for cases where the primary crashes after shipping a WAL segment that ends with a partial WAL record (Álvaro Herrera)

    If the primary did not survive long enough to finish writing the rest of the incomplete WAL record, then the previous crash-recovery logic had it back up and overwrite WAL starting from the beginning of the incomplete WAL record. This is problematic since standby servers may already have copies of that WAL segment. They will then see an inconsistent next segment, and will not be able to recover without manual intervention. To fix, do not back up over a WAL segment boundary when restarting after a crash. Instead write a new type of WAL record at the start of the next WAL segment, informing readers that the incomplete WAL record will never be finished and must be disregarded.

    When applying this update, it's best to update standby servers before the primary, so that they will be ready to handle this new WAL record type if the primary happens to crash.

  • Fix CREATE INDEX CONCURRENTLY to wait for the latest prepared transactions (Andrey Borodin)

    Rows inserted by just-prepared transactions might be omitted from the new index, causing queries relying on the index to miss such rows. The previous fix for this type of problem failed to account for PREPARE TRANSACTION commands that were still in progress when CREATE INDEX CONCURRENTLY checked for them. As before, in installations that have enabled prepared transactions (max_prepared_transactions > 0), it's recommended to reindex any concurrently-built indexes in case this problem occurred when they were built.

  • Avoid race condition that can cause backends to fail to add entries for new rows to an index being built concurrently (Noah Misch, Andrey Borodin)

    While it's apparently rare in the field, this case could potentially affect any index built or reindexed with the CONCURRENTLY option. It is recommended to reindex any such indexes to make sure they are correct.

  • Fix float4 and float8 hash functions to produce uniform results for NaNs (Tom Lane)

    Since PostgreSQL's floating-point types deem all NaNs to be equal, it's important for the hash functions to produce the same hash code for all bit-patterns that are NaNs according to the IEEE 754 standard. This failed to happen before, meaning that hash indexes and hash-based query plans might produce incorrect results for non-canonical NaN values. ('-NaN'::float8 is one way to produce such a value on most machines.) It is advisable to reindex hash indexes on floating-point columns, if there is any possibility that they might contain such values.

  • Prevent data loss during crash recovery of CREATE TABLESPACE, when wal_level = minimal (Noah Misch)

    If the server crashed between CREATE TABLESPACE and the next checkpoint, replay would fully remove the contents of the new tablespace's directory, relying on subsequent WAL replay to restore everything within that directory. This interacts badly with optimizations that skip writing WAL (one example is COPY into a just-created table). Such optimizations are applied only when wal_level is minimal, which is not the default in v10 and later.

  • Ensure that the relation cache is invalidated for a table being attached to or detached from a partitioned table (Amit Langote, Álvaro Herrera)

    This oversight could allow misbehavior of subsequent inserts/updates addressed directly to the partition, but only in currently-existing sessions.

  • Ensure that the relation cache is invalidated when creating or dropping a FOR ALL TABLES publication (Hou Zhijie, Vignesh C)

    This oversight could lead to improper replication behavior until all currently-existing sessions have exited.

  • Don't discard a cast to the same type with unspecified type modifier (Tom Lane)

    For example, if column f1 is of type numeric(18,3), the parser used to simply discard a cast like f1::numeric, on the grounds that it would have no run-time effect. That's true, but the exposed type of the expression should still be considered to be plain numeric, not numeric(18,3). This is important for correctly resolving the type of larger constructs, such as recursive UNIONs.

  • Fix updates of element fields in arrays of domain over composite (Tom Lane)

    A command such as UPDATE tab SET fld[1].subfld = val failed if the array's elements were domains rather than plain composites.

  • Disallow creating an ICU collation if the current database's encoding won't support it (Tom Lane)

    Previously this was allowed, but then the collation could not be referenced because of the way collation lookup works; you could not use the collation, nor even drop it.

  • Fix corner-case loss of precision in numeric power() (Dean Rasheed)

    The result could be inaccurate when the first argument is very close to 1.

  • Avoid regular expression errors with capturing parentheses inside {0} (Tom Lane)

    Regular expressions like (.){0}...\1 drew “invalid backreference number”. Other regexp engines such as Perl don't complain, though, and for that matter ours doesn't either in some closely related cases. Worse, it could throw an assertion failure instead. Fix it so that no error is thrown and instead the back-reference is silently deemed to never match.

  • Prevent regular expression back-references from sometimes matching when they shouldn't (Tom Lane)

    The regexp engine was careless about clearing match data for capturing parentheses after rejecting a partial match. This could allow a later back-reference to match in places where it should fail for lack of a defined referent.

  • Fix regular expression performance bug with back-references inside iteration nodes (Tom Lane)

    Incorrect back-tracking logic could result in exponential time spent looking for a match. Fortunately the problem is masked in most cases by other optimizations.

  • Fix incorrect results from AT TIME ZONE applied to a time with time zone value (Tom Lane)

    The results were incorrect if the target time zone was specified by a dynamic timezone abbreviation (that is, one that is defined as equivalent to a full time zone name, rather than a fixed UTC offset).

  • Fix mistranslation of PlaceHolderVars to inheritance child relations (Tom Lane)

    This error could result in assertion failures, or in mis-planning of queries having partitioned or inherited tables on the nullable side of an outer join.

  • Avoid using MCV-only statistics to estimate the range of a column (Tom Lane)

    There are corner cases in which ANALYZE will build a most-common-values (MCV) list but not a histogram, even though the MCV list does not account for all the observed values. In such cases, keep the planner from using the MCV list alone to estimate the range of column values.

  • Fix restoration of a Portal's snapshot inside a subtransaction (Bertrand Drouvot)

    If a procedure commits or rolls back a transaction, and then its next significant action is inside a new subtransaction, snapshot management went wrong, leading to a dangling pointer and probable crash. A typical example in PL/pgSQL is a COMMIT immediately followed by a BEGIN ... EXCEPTION block that performs a query.

  • Clean up correctly if a transaction fails after exporting its snapshot (Dilip Kumar)

    This oversight would only cause a problem if the same session attempted to export a snapshot again. The most likely scenario for that is creation of a replication slot (followed by rollback) and then creation of another replication slot.

  • Prevent wraparound of overflowed-subtransaction tracking on standby servers (Kyotaro Horiguchi, Alexander Korotkov)

    This oversight could cause significant performance degradation (manifesting as excessive SubtransSLRU traffic) on standby servers.

  • Ensure that prepared transactions are properly accounted for during promotion of a standby server (Michael Paquier, Andres Freund)

    There was a narrow window where a prepared transaction could be omitted from a snapshot taken by a concurrently-running session. If that session then used the snapshot to perform data updates, erroneous results or data corruption could occur.

  • Refuse to rewind a cursor marked NO SCROLL if it has been held over from a previous transaction due to the WITH HOLD option (Tom Lane)

    We have long forbidden fetching backwards from a NO SCROLL cursor, but for historical reasons the prohibition didn't extend to cases in which we rewind the query altogether and then re-fetch forwards. That exception leads to inconsistencies, particularly for held-over cursors which may not have stored all the data necessary to rewind. Disallow rewinding for non-scrollable held-over cursors to block the worst inconsistencies. (v15 will remove the exception altogether.)

  • Fix possible failure while saving a WITH HOLD cursor at transaction end, if it had already been read to completion (Tom Lane)

  • Fix detection of a relation that has grown to the maximum allowed length (Tom Lane)

    An attempt to extend a table or index past the limit of 2^32-1 blocks was rejected, but not soon enough to prevent inconsistent internal state from being created.

  • Correctly track the presence of data-modifying CTEs when expanding a DO INSTEAD rule (Greg Nancarrow, Tom Lane)

    The previous failure to do this could lead to problems such as unsafely choosing a parallel plan.

  • Fix incorrect reporting of permissions failures on extended statistics objects (Tomas Vondra)

    The code typically produced “cache lookup error” rather than the intended message.

  • Fix incorrect snapshot handling in parallel workers (Greg Nancarrow)

    This oversight could lead to misbehavior in parallel queries if the transaction isolation level is less than REPEATABLE READ.

  • Fix logical decoding to correctly ignore toast-table changes for transient tables (Bertrand Drouvot)

    Logical decoding normally ignores changes in transient tables such as those created during an ALTER TABLE heap rewrite. But that filtering wasn't applied to the associated toast table if any, leading to possible errors when rewriting a table that's being published.

  • Ensure that walreceiver processes create all required archive notification files before exiting (Fujii Masao)

    If a walreceiver exited exactly at a WAL segment boundary, it failed to make a notification file for the last-received segment, thus delaying archiving of that segment on the standby.

  • Avoid trying to lock the OLD and NEW pseudo-relations in a rule that uses SELECT FOR UPDATE (Masahiko Sawada, Tom Lane)

  • Fix parser's processing of aggregate FILTER clauses (Tom Lane)

    If the FILTER expression is a plain boolean column, the semantic level of the aggregate could be mis-determined, leading to not-per-spec behavior. If the FILTER expression is itself a boolean-returning aggregate, an error should be thrown but was not, likely resulting in a crash at execution.

  • Ensure that the correct lock level is used when renaming a table (Nathan Bossart, Álvaro Herrera)

    For historical reasons, ALTER INDEX ... RENAME can be applied to any sort of relation. The lock level required to rename an index is lower than that required to rename a table or other kind of relation, but the code got this wrong and would use the weaker lock level whenever the command is spelled ALTER INDEX.

  • Avoid trying to clean up LLVM state after an error within LLVM (Andres Freund, Justin Pryzby)

    This prevents a likely crash during backend exit after a fatal LLVM error.

  • Avoid null-pointer-dereference crash when dropping a role that owns objects being dropped concurrently (Álvaro Herrera)

  • Prevent “snapshot reference leak” warning when lo_export() or a related function fails (Heikki Linnakangas)

  • Ensure that scans of SP-GiST indexes are counted in the statistics views (Tom Lane)

    Incrementing the number-of-index-scans counter was overlooked in the SP-GiST code, although per-tuple counters were advanced correctly.

  • Recalculate relevant wait intervals if recovery_min_apply_delay is changed during recovery (Soumyadeep Chakraborty, Ashwin Agrawal)

  • Fix infinite loop if a simplehash.h hash table reaches 2^32 elements (Yura Sokolov)

    It seems unlikely that this bug has been hit in practice, as it would require work_mem settings of hundreds of gigabytes for existing uses of simplehash.h.

  • Reduce memory consumption during calculation of extended statistics (Justin Pryzby, Tomas Vondra)

  • Disallow setting huge_pages to on when shared_memory_type is sysv (Thomas Munro)

    Previously, this setting was accepted, but it did nothing for lack of any implementation.

  • Fix ecpg to recover correctly after malloc() failure while establishing a connection (Michael Paquier)

  • Fix misevaluation of stable functions called in the arguments of a PL/pgSQL CALL statement (Tom Lane)

    They were being called with an out-of-date snapshot, so that they would not see any database changes made since the start of the session's top-level command.

  • Allow EXIT out of the outermost block in a PL/pgSQL routine (Tom Lane)

    If the routine does not require an explicit RETURN, this usage should be valid, but it was rejected.

  • Remove pg_ctl's hard-coded limits on the total length of generated commands (Phil Krylov)

    For example, this removes a restriction on how many command-line options can be passed through to the postmaster. Individual path names that pg_ctl deals with, such as the postmaster executable's name or the data directory name, are still limited to MAXPGPATH bytes in most cases.

  • Fix pg_dump to dump non-global default privileges correctly (Neil Chen, Masahiko Sawada)

    If a global (unrestricted) ALTER DEFAULT PRIVILEGES command revoked some present-by-default privilege, for example EXECUTE for functions, and then a restricted ALTER DEFAULT PRIVILEGES command granted that privilege again for a selected role or schema, pg_dump failed to dump the restricted privilege grant correctly.

  • Make pg_dump acquire shared lock on partitioned tables that are to be dumped (Tom Lane)

    This oversight was usually pretty harmless, since once pg_dump has locked any of the leaf partitions, that would suffice to prevent significant DDL on the partitioned table itself. However problems could ensue when dumping a childless partitioned table, since no relevant lock would be held.

  • Improve pg_dump's performance by avoiding making per-table queries for RLS policies, and by avoiding repetitive calls to format_type() (Tom Lane)

    These changes provide only marginal improvement when dumping from a local server, but a dump from a remote server can benefit substantially due to fewer network round-trips.

  • Fix crash in pg_dump when attempting to dump trigger definitions from a pre-8.3 server (Tom Lane)

  • Fix incorrect filename in pg_restore's error message about an invalid large object TOC file (Daniel Gustafsson)

  • Ensure that pgbench exits with non-zero status after a socket-level failure (Yugo Nagata, Fabien Coelho)

    The desired behavior is to finish out the run but then exit with status 2. Also, fix the reporting of such errors.

  • Fix failure of contrib/btree_gin indexes on "char" (not char(n)) columns, when an indexscan using the < or <= operator is performed (Tom Lane)

    Such an indexscan failed to return all the entries it should.

  • Change contrib/pg_stat_statements to read its “query texts” file in units of at most 1GB (Tom Lane)

    Such large query text files are very unusual, but if they do occur, the previous coding would fail on Windows 64 (which rejects individual read requests of more than 2GB).

  • Fix null-pointer crash when contrib/postgres_fdw tries to report a data conversion error (Tom Lane)

  • Add spinlock support for the RISC-V architecture (Marek Szuba)

    This is essential for reasonable performance on that platform.

  • Support OpenSSL 3.0.0 (Peter Eisentraut, Daniel Gustafsson, Michael Paquier)

  • Set correct type identifier on OpenSSL BIO (I/O abstraction) objects created by PostgreSQL (Itamar Gafni)

    This oversight probably only matters for code that is doing tasks like auditing the OpenSSL installation. But it's nominally a violation of the OpenSSL API, so fix it.

  • Fix our pkg-config files to again support static linking of libpq (Peter Eisentraut)

  • Make pg_regexec() robust against an out-of-range search_start parameter (Tom Lane)

    Return REG_NOMATCH, instead of possibly crashing, when search_start is past the end of the string. This case is probably unreachable within core PostgreSQL, but extensions might be more careless about the parameter value.

  • Ensure that GetSharedSecurityLabel() can be used in a newly-started session that has not yet built its critical relation cache entries (Jeff Davis)

  • Use the CLDR project's data to map Windows time zone names to IANA time zones (Tom Lane)

    When running on Windows, initdb attempts to set the new cluster's timezone parameter to the IANA time zone matching the system's prevailing time zone. We were using a mapping table that we'd generated years ago and updated only fitfully; unsurprisingly, it contained a number of errors as well as omissions of recently-added zones. It turns out that CLDR has been tracking the most appropriate mappings, so start using their data. This change will not affect any existing installation, only newly-initialized clusters.

  • Update time zone data files to tzdata release 2021e for DST law changes in Fiji, Jordan, Palestine, and Samoa, plus historical corrections for Barbados, Cook Islands, Guyana, Niue, Portugal, and Tonga.

    Also, the Pacific/Enderbury zone has been renamed to Pacific/Kanton. Also, the following zones have been merged into nearby, more-populous zones whose clocks have agreed with them since 1970: Africa/Accra, America/Atikokan, America/Blanc-Sablon, America/Creston, America/Curacao, America/Nassau, America/Port_of_Spain, Antarctica/DumontDUrville, and Antarctica/Syowa. In all these cases, the previous zone name remains as an alias.

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