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
2015-06-04
9.1.17 HistoricalSupport ends 2016-10-27
A dump/restore is not required for those running 9.1.X.
However, if you are upgrading from a version earlier than 9.1.16, see Section E.9.
Changes
Avoid failures while fsync'ing data directory during crash restart (Abhijit Menon-Sen, Tom Lane)
In the previous minor releases we added a patch to fsync everything in the data directory after a crash. Unfortunately its response to any error condition was to fail, thereby preventing the server from starting up, even when the problem was quite harmless. An example is that an unwritable file in the data directory would prevent restart on some platforms; but it is common to make SSL certificate files unwritable by the server. Revise this behavior so that permissions failures are ignored altogether, and other types of failures are logged but do not prevent continuing.
“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 configure's check prohibiting linking to a threaded libpython on OpenBSD (Tom Lane)
The failure this restriction was meant to prevent seems to not be a problem anymore on current OpenBSD versions.
“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 libpq to use TLS protocol versions beyond v1 (Noah Misch)
For a long time, libpq was coded so that the only SSL protocol it would allow was TLS v1. Now that newer TLS versions are becoming popular, allow it to negotiate the highest commonly-supported TLS version with the server. (PostgreSQL servers were already capable of such negotiation, so no change is needed on the server side.) This is a back-patch of a change already released in 9.4.0.
“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.