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POSTGRESQL · VERSION COMPARE
All features, fixes, and compatibility notes in this release, with related records from other versions.
Includes changes after the source version through the target. A major version name means its initial release.
From PostgreSQL 9.0 onward: 17 major branches and 352 release notes. Updated 2026-09-26.
Complete release changes
2021-02-11
9.5.25 HistoricalSupport ends 2021-02-11
A dump/restore is not required for those running 9.5.X.
However, see the first changelog item below, which describes cases in which reindexing indexes after the upgrade may be advisable.
Also, if you are upgrading from a version earlier than 9.5.20, see Section E.6.
Changes
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.
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
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.
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
Fix crash when WHERE CURRENT OF is applied to a cursor whose plan contains a custom scan node (David Geier)
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
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.
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
Be more careful about whether index AMs support mark/restore (Andrew Gierth)
This prevents errors about missing support functions in rare edge cases.
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
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.
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
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.
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
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.
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
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.
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
Disallow converting an inheritance child table to a view (Tom Lane)
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
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.
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
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.
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
Avoid preallocating executor hash tables in EXPLAIN without ANALYZE (Alexey Bashtanov)
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
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.
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
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.
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
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.
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
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.
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
Fix memory leak in walsender processes while sending new snapshots for logical decoding (Amit Kapila)
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
Fix walsender to accept additional commands after terminating replication (Jeff Davis)
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
Avoid assertion failure in pg_get_functiondef() when examining a function with a TRANSFORM option (Tom Lane)
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
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).
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
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.
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
In pg_rewind, ensure that all WAL is accounted for when rewinding a standby server (Ian Barwick, Heikki Linnakangas)
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
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.
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
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.
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
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.
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
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.
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
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)
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
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.
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
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.
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
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.
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
Changes
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.
“Same change” requires complete matching evidence. “Related commits” can cover independent changes, a partial backport, or a follow-up correction; each release keeps its own explanation.
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The comparison follows PostgreSQL release notes from just after the source through the target version. For a major upgrade, maintenance releases from each older branch are included only up to the next major release date, and never after the target date. A major version such as 18 means its initial release, 18.0. Previews and development snapshots are labeled separately.
Entries come from the original English manuals. Release coverage and commit evidence are verified against upstream sources. Every entry retains its complete explanation and source link. Categories aid browsing; read the full notes for impact, conditions, and migration steps.
Fixes can be backported to several branches. Confirmed duplicates are merged conservatively, with every branch explanation retained. A note describing several independent fixes is excluded only when all are already present in the source. Major-release features remain distinct from related maintenance patches unless their complete original descriptions match. Uncertain matches are retained. This is a release-note history, not an exhaustive comparison of compiled binaries.
CVE results are calculated independently from the PostgreSQL security registry and vulnerability records. A CVE counts as gained protection only when the source is affected and the target is fixed or unaffected. Remaining vulnerabilities are listed separately. Security entries and distinct CVEs are counted separately.
Interaction inspired by pgversions.com and pgversionreport. Content comes from PostgreSQL release notes. See the release notes archive.