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
2019-05-09
9.4.22 HistoricalSupport ends 2020-02-13
A dump/restore is not required for those running 9.4.X.
However, if you are upgrading from a version earlier than 9.4.18, see Section E.9.
Changes
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.
“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 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.
“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 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.
“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
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.
“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 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.
“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 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.
“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
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".
“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 "failed to build any N-way joins" planner failures with lateral references leading out of FULL outer joins (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
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.
“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 O(N^2) performance issue when rolling back a transaction that created many tables (Tomas Vondra)
“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 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.
“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 which a hot-standby postmaster could fail to shut down after receiving a smart-shutdown request (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
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.
“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 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.
“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 NaN as a value for floating-point server parameters (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
Rearrange REINDEX processing to avoid assertion failures when reindexing individual indexes of pg_class (Andres Freund, 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 planner assertion failure for parameterized dummy paths (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
Insert correct test function in the result of SnapBuildInitialSnapshot() (Antonin Houska)
No core code cares about this, but some extensions do.
“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 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.
“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 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.
“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 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.
“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 buffer overruns in ecpg's processing of include filenames (Liu Huailing, Fei Wu)
“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 in contrib/vacuumlo if an lo_unlink() call failed (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
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.
“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 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.
“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.