DocumentationVersion comparison
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
2016-03-31
9.5.2 HistoricalSupport ends 2021-02-11
| CVE / issue | Severity | Fixed version |
|---|---|---|
| CVE-2016-2193 Maintain row-security status properly in cached plans | 4.2 | 9.5.2 |
| CVE-2016-3065 Add must-be-superuser checks to some new contrib/pageinspect functions | 3.1 | 9.5.2 |
A dump/restore is not required for those running 9.5.X.
However, you may need to REINDEX some indexes after applying the update, as per the first changelog entry below.
Changes
Disable abbreviated keys for string sorting in non-C locales (Robert Haas)
PostgreSQL 9.5 introduced logic for speeding up comparisons of string data types by using the standard C library function strxfrm() as a substitute for strcoll(). It now emerges that most versions of glibc (Linux's implementation of the C library) have buggy implementations of strxfrm() that, in some locales, can produce string comparison results that do not match strcoll(). Until this problem can be better characterized, disable the optimization in all non-C locales. (C locale is safe since it uses neither strcoll() nor strxfrm().)
Unfortunately, this problem affects not only sorting but also entry ordering in B-tree indexes, which means that B-tree indexes on text, varchar, or char columns may now be corrupt if they sort according to an affected locale and were built or modified under PostgreSQL 9.5.0 or 9.5.1. Users should REINDEX indexes that might be affected.
It is not possible at this time to give an exhaustive list of known-affected locales. C locale is known safe, and there is no evidence of trouble in English-based locales such as en_US, but some other popular locales such as de_DE are affected in most glibc versions.
Changes
Maintain row-security status properly in cached plans (Stephen Frost)
In a session that performs queries as more than one role, the plan cache might incorrectly re-use a plan that was generated for another role ID, thus possibly applying the wrong set of policies when row-level security (RLS) is in use. (CVE-2016-2193)
Changes
Add must-be-superuser checks to some new contrib/pageinspect functions (Andreas Seltenreich)
Most functions in the pageinspect extension that inspect bytea values disallow calls by non-superusers, but brin_page_type() and brin_metapage_info() failed to do so. Passing contrived bytea values to them might crash the server or disclose a few bytes of server memory. Add the missing permissions checks to prevent misuse. (CVE-2016-3065)
Changes
Fix incorrect handling of indexed ROW() comparisons (Simon Riggs)
Flaws in a minor optimization introduced in 9.5 caused incorrect results if the ROW() comparison matches the index ordering partially but not exactly (for example, differing column order, or the index contains both ASC and DESC columns). Pending a better solution, the optimization has been removed.
Changes
Fix incorrect handling of NULL index entries in indexed ROW() comparisons (Tom Lane)
An index search using a row comparison such as ROW(a, b) > ROW('x', 'y') would stop upon reaching a NULL entry in the b column, ignoring the fact that there might be non-NULL b values associated with later values of a.
“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 unlikely data-loss scenarios due to renaming files without adequate fsync() calls before and after (Michael Paquier, Tomas Vondra, Andres Freund)
“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 incorrect behavior when rechecking a just-modified row in a query that does SELECT FOR UPDATE/SHARE and contains some relations that need not be locked (Tom Lane)
Rows from non-locked relations were incorrectly treated as containing all NULLs during the recheck, which could result in incorrectly deciding that the updated row no longer passes the WHERE condition, or in incorrectly outputting NULLs.
Changes
Fix bug in json_to_record() when a field of its input object contains a sub-object with a field name matching one of the requested output column names (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
Fix nonsense result from two-argument form of jsonb_object() when called with empty arrays (Michael Paquier, Andrew Dunstan)
Changes
Fix misbehavior in jsonb_set() when converting a path array element into an integer for use as an array subscript (Michael Paquier)
Changes
Fix misformatting of negative time zone offsets by to_char()'s OF format code (Thomas Munro, 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
Fix possible incorrect logging of waits done by INSERT ... ON CONFLICT (Peter Geoghegan)
Log messages would sometimes claim that the wait was due to an exclusion constraint although no such constraint was responsible.
Changes
Ignore recovery_min_apply_delay parameter until recovery has reached a consistent state (Michael Paquier)
Previously, standby servers would delay application of WAL records in response to recovery_min_apply_delay even while replaying the initial portion of WAL needed to make their database state valid. Since the standby is useless until it's reached a consistent database state, this was deemed unhelpful.
“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
Correctly handle cases where pg_subtrans is close to XID wraparound during server startup (Jeff Janes)
“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 logical decoding (Andres Freund)
Trouble cases included tuples larger than one page when replica identity is FULL, UPDATEs that change a primary key within a transaction large enough to be spooled to disk, incorrect reports of "subxact logged without previous toplevel record", and incorrect reporting of a transaction's commit time.
“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 error with nested security barrier views when the outer view has a WHERE clause containing a correlated subquery (Dean Rasheed)
“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 GIN index searches (Tom Lane)
Changes
Fix corner-case crash due to trying to free localeconv() output strings more than once (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
Fix parsing of affix files for ispell dictionaries (Tom Lane)
The code could go wrong if the affix file contained any characters whose byte length changes during case-folding, for example I in Turkish UTF8 locales.
“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 use of sscanf() to parse ispell dictionary files (Artur Zakirov)
This dodges a portability problem on FreeBSD-derived platforms (including macOS).
“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 atomic-operations code used on PPC with IBM's xlc compiler (Noah Misch)
This error led to rare failures of concurrent operations on that platform.
Changes
Avoid a crash on old Windows versions (before 7SP1/2008R2SP1) with an AVX2-capable CPU and a Postgres build done with Visual Studio 2013 (Christian Ullrich)
This is a workaround for a bug in Visual Studio 2013's runtime library, which Microsoft have stated they will not fix in that version.
“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 psql's tab completion logic to handle multibyte characters properly (Kyotaro Horiguchi, Robert Haas)
“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 psql's tab completion for SECURITY LABEL (Tom Lane)
Pressing TAB after SECURITY LABEL might cause a crash or offering of inappropriate keywords.
“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
Make pg_ctl accept a wait timeout from the PGCTLTIMEOUT environment variable, if none is specified on the command line (Noah Misch)
This eases testing of slower buildfarm members by allowing them to globally specify a longer-than-normal timeout for postmaster startup and shutdown.
“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 incorrect test for Windows service status in pg_ctl (Manuel Mathar)
The previous set of minor releases attempted to fix pg_ctl to properly determine whether to send log messages to Window's Event Log, but got the test backwards.
“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 pgbench to correctly handle the combination of -C and -M prepared options (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 pg_upgrade, skip creating a deletion script when the new data directory is inside the old data directory (Bruce Momjian)
Blind application of the script in such cases would result in loss of the new data directory.
“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 PL/Perl, properly translate empty Postgres arrays into empty Perl arrays (Alex Hunsaker)
“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
Make PL/Python cope with function names that aren't valid Python identifiers (Jim Nasby)
“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 multiple mistakes in the statistics returned by contrib/pgstattuple's pgstatindex() function (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
Remove dependency on psed in MSVC builds, since it's no longer provided by core Perl (Michael Paquier, Andrew Dunstan)
“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 2016c for DST law changes in Azerbaijan, Chile, Haiti, Palestine, and Russia (Altai, Astrakhan, Kirov, Sakhalin, Ulyanovsk regions), plus historical corrections for Lithuania, Moldova, and Russia (Kaliningrad, Samara, Volgograd).
“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.
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