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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
2025-05-08
16.9 SupportedSupport ends 2028-11-09
| CVE / issue | Severity | Fixed version |
|---|---|---|
| CVE-2025-4207 Avoid one-byte buffer overread when examining invalidly-encoded strings that are claimed to be in GB18030 encoding | 5.9 | 16.9 |
A dump/restore is not required for those running 16.X.
However, if you have any self-referential foreign key constraints on partitioned tables, it may be necessary to recreate those constraints to ensure that they are being enforced correctly. See the second changelog entry below.
Also, if you have any BRIN bloom indexes, it may be advisable to reindex them after updating. See the third changelog entry below.
Also, if you are upgrading from a version earlier than 16.5, see Section E.11.
Changes
Avoid one-byte buffer overread when examining invalidly-encoded strings that are claimed to be in GB18030 encoding (Noah Misch, Andres Freund) § §
While unlikely, a SIGSEGV crash could occur if an incomplete multibyte character appeared at the end of memory. This was possible both in the server and in libpq-using applications. (CVE-2025-4207)
“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
Handle self-referential foreign keys on partitioned tables correctly (Álvaro Herrera) §
Creating or attaching partitions failed to make the required catalog entries for a foreign-key constraint, if the table referenced by the constraint was the same partitioned table. This resulted in failure to enforce the constraint fully.
To fix this, you should drop and recreate any self-referential foreign keys on partitioned tables, if partitions have been created or attached since the constraint was created. Bear in mind that violating rows might already be present, in which case recreating the constraint will fail, and you'll need to fix up those rows before trying again.
“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 data loss when merging compressed BRIN summaries in brin_bloom_union() (Tomas Vondra) §
The code failed to account for decompression results not being identical to the input objects, which would result in failure to add some of the data to the merged summary, leading to missed rows in index searches.
This mistake was present back to v14 where BRIN bloom indexes were introduced, but this code path was only rarely reached then. It's substantially more likely to be hit in v17 because parallel index builds now use the code.
“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 unexpected “attribute has wrong type” errors in UPDATE, DELETE, and MERGE queries that use whole-row table references to views or functions in FROM (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 MERGE into a partitioned table with DO NOTHING actions (Tender Wang) §
Some cases failed with “unknown action in MERGE WHEN clause” 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
Prevent failure in INSERT commands when the table has a GENERATED column of a domain data type and the domain's constraints disallow null values (Jian He) §
Constraint failure was reported even if the generation expression produced a perfectly okay result.
“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 process references to outer CTE names that appear within a WITH clause attached to an INSERT/UPDATE/DELETE/MERGE command that's inside WITH (Tom Lane) §
The parser failed to detect disallowed recursion cases, nor did it account for such references when sorting CTEs into a usable order.
“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
Don't try to parallelize array_agg() when the argument is of an anonymous record type (Richard Guo, Tom Lane) §
The protocol for communicating with parallel workers doesn't support identifying the concrete record type that a worker is returning.
“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 ARRAY( and subquery)ARRAY[ constructs to produce sane results when the input is of type expression, ...]int2vector or oidvector (Tom Lane) §
This patch restores the behavior that existed before PostgreSQL 9.5: the result is of type int2vector[] or oidvector[].
“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 erroneous reports of invalid affixes while parsing Ispell dictionaries (Jacob Brazeal) §
“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 TABLE ADD COLUMN to correctly handle the case of a domain type that has a default (Jian He, Tom Lane, Tender Wang) § §
If a domain type has a default, adding a column of that type (without any explicit DEFAULT clause) failed to install the domain's default value in existing rows, instead leaving the new column null.
“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
Repair misbehavior when there are duplicate column names in a foreign key constraint's ON DELETE SET DEFAULT or SET NULL action (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
Improve the error message for disallowed attempts to alter the properties of a foreign key constraint (Álvaro Herrera) §
“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 error when resetting the relhassubclass flag of a temporary table that's marked ON COMMIT DELETE ROWS (Noah Misch) §
“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
Add missing deparsing of the INDENT option of XMLSERIALIZE() (Jim Jones) § §
Previously, views or rules using XMLSERIALIZE(... INDENT) were dumped without the INDENT clause, causing incorrect results after restore.
“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 premature evaluation of the arguments of an aggregate function that has both FILTER and ORDER BY (or DISTINCT) options (David Rowley) §
If there is ORDER BY or DISTINCT, we consider pre-sorting the aggregate input values rather than doing the sort within the Agg plan node. But this is problematic if the aggregate inputs include expressions that could fail (for example, a division where some of the input divisors could be zero) and there is a FILTER clause that's meant to prevent such failures. Pre-sorting would push the expression evaluations to before the FILTER test, allowing the failures to happen anyway. Avoid this by not pre-sorting if there's a FILTER and the input expressions are anything more complex than a simple Var or Const.
“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 failure to identify more than one hashable ScalarArrayOpExpr subexpression within a top-level expression (David Geier) §
This resulted in unnecessarily-inefficient execution of any additional subexpressions that could have been processed with a hash table (that is, IN, NOT IN, or = ANY clauses with all-constant right-hand sides).
“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
Disable “skip fetch” optimization in bitmap heap scan (Matthias van de Meent) §
It turns out that this optimization can result in returning dead tuples when a concurrent vacuum marks a page all-visible.
“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 performance issues in GIN index search startup when there are many search keys (Tom Lane, Vinod Sridharan) § §
An indexable clause with many keys (for example, jsonbcol ?| array[...] with tens of thousands of array elements) took O(N2) time to start up, and was uncancelable for that interval too.
“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
Detect missing support procedures in a BRIN index operator class, and report an error instead of crashing (Álvaro Herrera) §
“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
Respond to interrupts (such as query cancel) while waiting for asynchronous subplans of an Append plan node (Heikki Linnakangas) §
Previously, nothing would happen until one of the subplans becomes ready.
“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 I/O statistics of active WAL senders more frequently (Bertrand Drouvot) §
Previously, the pg_stat_io view failed to accumulate I/O performed by a WAL sender until that process exited. Now such I/O will be reported after at most one second's delay.
“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 race condition in handling of synchronous_standby_names immediately after startup (Melnikov Maksim, Michael Paquier) §
For a short period after system startup, backends might fail to wait for synchronous commit even though synchronous_standby_names is 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
Avoid infinite loop if scram_iterations is set to INT_MAX (Kevin K Biju) §
“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 possible crashes due to double transformation of json_array()'s subquery (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 pg_strtof() to not crash with null endptr (Alexander Lakhin, 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 crash after out-of-memory in certain GUC assignments (Daniel Gustafsson) §
“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 crash when a Snowball stemmer encounters an out-of-memory condition (Maksim 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
Disallow copying of invalidated replication slots (Shlok Kyal) §
This prevents trouble when the invalid slot points to WAL that's already been removed.
“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 restoring logical replication slots on standby servers that are not in hot-standby mode (Masahiko Sawada) §
This prevents a scenario where the slot could remain valid after promotion even if wal_level is too low.
“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 over-advancement of catalog xmin in “fast forward” mode of logical decoding (Zhijie Hou) §
This mistake could allow deleted catalog entries to be vacuumed away even though they were still potentially needed by the WAL-reading process.
“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 data loss when DDL operations that don't take a strong lock affect tables that are being logically replicated (Shlok Kyal, Hayato Kuroda) § §
The catalog changes caused by the DDL command were not reflected into WAL-decoding processes, allowing them to decode subsequent changes using stale catalog data, probably resulting in data corruption.
“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 incorrect reset of replication origin when an apply worker encounters an error but the error is caught and does not result in worker exit (Hayato Kuroda) §
This mistake could allow duplicate data to be applied.
“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
“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 detection of mixed-origin subscriptions (Hou Zhijie, Shlok Kyal) §
Subscription creation gives a warning if a subscribed-to table is also being followed through other publications, since that could cause duplicate data to be received. This change improves that logic to also detect cases where a partition parent or child table is the one being followed through another publication.
“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 wrong checkpoint details in error message about incorrect recovery timeline choice (David Steele) §
If the requested recovery timeline is not reachable, the reported checkpoint and timeline should be the values read from the backup_label, if there is one. This message previously reported values from the control file, which is correct when recovering from the control file without a backup_label, but not when there is a backup_label.
“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 incorrect assertion in pgstat_report_stat() (Michael Paquier) §
“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 overly-strict assertion in gistFindCorrectParent() (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
Fix rare assertion failure in standby servers when the primary is restarted (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
In PL/pgSQL, avoid “unexpected plan node type” error when a scrollable cursor is defined on a simple SELECT query (Andrei Lepikhov) §expression
“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
Don't try to drop individual index partitions in pg_dump's --clean mode (Jian He) §
The server rejects such DROP commands. That has no real consequences, since the partitions will go away anyway in the subsequent DROPs of either their parent tables or their partitioned index. However, the error reported for the attempted drop causes problems when restoring in --single-transaction mode.
“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_dumpall, avoid emitting invalid role GRANT commands if pg_auth_members contains invalid role OIDs (Tom Lane) §
Instead, print a warning and skip the entry. This copes better with catalog corruption that has been seen to occur in back branches as a result of race conditions between GRANT and DROP ROLE.
“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_amcheck and pg_upgrade, use the correct function to free allocations made by libpq (Michael Paquier, Ranier Vilela) § § §
These oversights could result in crashes in certain Windows build configurations, such as a debug build of libpq used by a non-debug build of the calling application.
“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 contrib/dblink queries to be interrupted by query cancel (Noah Misch) §
This change back-patches a v17-era fix. It prevents possible hangs in CREATE DATABASE and DROP DATABASE due to failure to detect deadlocks.
“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 crashing with corrupt input data in contrib/pageinspect's heap_page_items() (Dmitry Kovalenko) §
“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 assertion failure in contrib/pg_freespacemap's pg_freespacemap() (Tender Wang) §
Applying pg_freespacemap() to a relation lacking storage (such as a view) caused an assertion failure, although there was no ill effect in non-assert builds. Add an error check to reject that case.
“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 build failure on macOS 15.4 (Tom Lane, Peter Eisentraut) §
This macOS update broke our configuration probe for strchrnul().
“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 2025b for DST law changes in Chile, plus historical corrections for Iran (Tom Lane) §
There is a new time zone America/Coyhaique for Chile's Aysén Region, to account for it changing to UTC-03 year-round and thus diverging from America/Santiago.
“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.