postgresql.git/doc/src/sgml/runtime.sgml, branch master

Remove pg_dump/pg_dumpall support for dumping from pre-v10 servers.

2026-07-02T18:05:50Z

Per discussion, it seems like a good time to bump the minimum supported version for various applications. Our current policy is to support at least 10 previous major versions, so this bumps the minimum to v10 for the v20 release. For reference, the minimum was last bumped to v9.2 in 2021 for v15 (see commits 30e7c175b8, e469f0aaf3, cf0cab868a, and 492046fa9e). As in previous changes of this sort, we aren't removing pg_restore's ability to read older archive files, though it's fair to wonder how that might be tested nowadays. For ease of review, and to be able to put the indentation changes in .git-blame-ignore-revs, I did not fix the indentation in this patch. I'll push a separate pgindent commit after these changes are applied. Reviewed-by: Fujii Masao Discussion: https://postgr.es/m/adZ4j88Dq9r8y9_9%40nathan

doc: Clean up title case use

2026-05-05T09:24:16Z

doc: Add missing GUCs to SSL SNI docs

2026-04-16T09:18:57Z

The ssl_sni and hosts_file GUCs were missing from the configuration section of the documentation, they were only described in the main SSL SNI subsection. This adds the GUCs to the relevant sections as well as rewords the existing SSL SNI documentation to refer to the settings along with a few smaller fixups. Author: Daniel Gustafsson Reported-by: Fujii Masao Reviewed-by: Fujii Masao Discussion: https://postgr.es/m/CAHGQGwESD2Pty+J1kP3mXmWwMKZ5uJmknZdJsSGrMSRR6CQBmw@mail.gmail.com

Doc: minor improvements to SNI documentation.

2026-03-23T19:33:51Z

My attention was drawn to this new documentation by overlength-line complaints in the PDF docs builds: the synopsis for hostname lines was too wide. I initially thought of shortening the parameter names to fit, but it turns out that adding markup is enough to persuade DocBook to break the line, and that seems more helpful anyway. While here, I couldn't resist some copy-editing, mostly being consistent about whether to use Oxford commas or not. The biggest change was to re-order the entries in the hostname-values table to match the running text.

ssl: Serverside SNI support for libpq

2026-03-18T11:37:11Z

Support for SNI was added to clientside libpq in 5c55dc8b4733 with the sslsni parameter, but there was no support for utilizing it serverside. This adds support for serverside SNI such that certificate/key handling is available per host. A new config file, $datadir/pg_hosts.conf, is used for configuring which certificate and key should be used for which hostname. In order to use SNI the ssl_sni GUC must be set to on, when it is off the ssl configuration works just like before. If ssl_sni is enabled and pg_hosts.conf is non-empty it will take precedence over the regular SSL GUCs, if it is empty or missing the regular GUCs will be used just as before this commit with no hostname specific handling. The TLS init hook is not compatible with ssl_sni since it operates on a single TLS configuration and SNI break that assumption. If the init hook and ssl_sni are both enabled, a WARNING will be issued. Host configuration can either be for a literal hostname to match, non- SNI connections using the no_sni keyword or a default fallback matching all connections. By omitting no_sni and the fallback a strict mode can be achieved where only connections using sslsni=1 and a specified hostname are allowed. CRL file(s) are applied from postgresql.conf to all configured hostnames. Serverside SNI requires OpenSSL, currently LibreSSL does not support the required infrastructure to update the SSL context during the TLS handshake. Author: Daniel Gustafsson Co-authored-by: Jacob Champion Reviewed-by: Jacob Champion Reviewed-by: Zsolt Parragi Reviewed-by: Chao Li Reviewed-by: Dewei Dai Reviewed-by: Cary Huang Reviewed-by: Heikki Linnakangas Discussion: https://postgr.es/m/1C81CD0D-407E-44F9-833A-DD0331C202E5@yesql.se

Switch the semaphore API on Solaris to unnamed POSIX.

2026-03-14T18:10:32Z

Solaris descendants (Illumos, OpenIndiana, OmniOS, etc.) hit System V semaphore limits ("No space left on device" from semget) when running many parallel test scripts under default system settings. We could tell people to raise those settings, but there's a better answer. Unnamed POSIX semaphores have been available on Solaris for decades and work well, so prefer them, as was recently done for AIX. This patch also updates the documentation to remove now-unnecessary advice about raising project.max-sem-ids and project.max-msg-ids. Author: Tom Lane Reviewed-by: Greg Burd Discussion: https://postgr.es/m/470305.1772417108@sss.pgh.pa.us

doc: Add restart on failure to example systemd file

2026-03-03T12:18:53Z

The documentation previously had a systemd unit file that would not attempt to recover from process failures such as OOM's, segfaults, etc. This commit adds "Restart=on-failure",` which tells systemd to attempt to restart the process after failure. This is the recommended configuration per the systemd documentation: "Setting this to on-failure is the recommended choice for long-running services". Many PostgreSQL users will simply copy/paste what the PostgreSQL documentation recommends and will probably do their own research and change the service file to restart on failure, so might as well set this as the default in the PostgreSQL documentation. Author: Andrew Jackson Discussion: https://www.postgresql.org/message-id/flat/CAKK5BkFfMpAQnv8CLs%3Di%3DrZwurtCV_gmfRb0uZi-V%2Bd6wcryqg%40mail.gmail.com

Restore AIX support.

2026-02-23T18:34:22Z

The concerns that led us to remove AIX support in commit 0b16bb877 have now been alleviated: 1. IBM has stepped forward to provide support, including buildfarm animal(s). 2. AIX 7.2 and later seem to be fine with large pg_attribute_aligned requirements. Since 7.1 is now EOL anyway, we can just cease to support it. 3. Tossing xlc support overboard seems okay as well. It's a bit sad to drop one of the few remaining non-gcc-alike compilers, but working around xlc's bugs and idiosyncrasies doesn't seem justified by the theoretical portability benefits. 4. Likewise, we can stop supporting 32-bit AIX builds. This is not so much about whether we could build such executables as that they're too much of a pain to manage in the field, due to limited address space available for dynamic library loading. 5. We hit on a way to manage catalog column alignment that doesn't require continuing developer effort (see commit ecae09725). Hence, this commit reverts 0b16bb877 and some follow-on commits such as e6bb491bf, except for not putting back XLC support nor the changes related to catalog column alignment. Some other notable changes from the way things were in v16: Prefer unnamed POSIX semaphores on AIX, rather than the default choice of SysV semaphores. Include /opt/freeware/lib in -Wl,-blibpath, even when it is not mentioned anywhere in LDFLAGS. Remove platform-specific adjustment of MEMSET_LOOP_LIMIT; maybe that's still the right thing, but it really ought to be re-tested. Silence compiler warnings related to getpeereid(), wcstombs_l(), and PAM conversation procs. Accept "libpythonXXX.a" as an okay name for the Python shared library (but only on AIX!). Author: Aditya Kamath Author: Srirama Kucherlapati Co-authored-by: Peter Eisentraut Reviewed-by: Tom Lane Discussion: https://postgr.es/m/CY5PR11MB63928CC05906F27FB10D74D0FD322@CY5PR11MB6392.namprd11.prod.outlook.com

Give up on running with NetBSD/OpenBSD's default semaphore settings.

2025-04-29T21:27:52Z

This reverts commit 38da053463bef32adf563ddee5277d16d2b6c5af, which attempted to preserve our ability to start with only 60 semaphores. Subsequent changes (particularly 55b454d0e) have put that idea pretty much permanently out of reach: people wishing to use Postgres v18 on OpenBSD or NetBSD will have no choice but to increase those platforms' default values of SEMMNI and SEMMNS. Hence, revert 38da05346's changes in SEMAS_PER_SET and the minimum tested value of max_connections. Adjust a comment from the subsequent patch 6d0154196, and tweak the wording in runtime.sgml to make it clear that changing SEMMNI/SEMMNS is no longer even a little bit optional on these platforms. Although 38da05346 was later back-patched into v17, leave that branch alone: it's still capable of starting with 60 semaphores, and there's no reason to break that. Author: Tom Lane Reviewed-by: Nathan Bossart Discussion: https://postgr.es/m/E1tuZNv-0037Gs-34@gemulon.postgresql.org Discussion: https://postgr.es/m/1052019.1745947915@sss.pgh.pa.us

doc: Clarify the system value for sslrootcert

2025-04-04T07:47:36Z

The documentation for the special value "system" for sslrootcert could be misinterpreted to mean the default operating system CA store, which it may be, but it's defined to be the default CA store of the SSL lib used. Backpatch down to v16 where support for the system value was added. Author: Daniel Gustafsson Reviewed-by: George MacKerron Discussion: https://postgr.es/m/B3CBBAA3-6EA3-4AB7-8619-4BBFAB93DDB4@yesql.se Backpatch-through: 16