Horton

Re: Enable data checksums by default

Christoph Berg <myon@debian.org>

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From: Christoph Berg <myon@debian.org>
To: Heikki Linnakangas <hlinnaka@iki.fi>
Cc: Peter Eisentraut <peter@eisentraut.org>, Tomas Vondra <tomas@vondra.me>, Nathan Bossart <nathandbossart@gmail.com>, Greg Sabino Mullane <htamfids@gmail.com>, Bruce Momjian <bruce@momjian.us>, Michael Paquier <michael@paquier.xyz>, Michael Banck <mbanck@gmx.net>, pgsql-hackers <pgsql-hackers@postgresql.org>
Date: 2025-06-05T10:37:02Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Avoid BufferGetLSNAtomic() calls during nbtree scans.

  2. doc PG 18 relnotes: Add incompatibility note about checksums now default

  3. Fix pg_upgrade's cross-version tests when old < 18

  4. initdb: Change default to using data checksums.

  5. Allow TAP tests to force checksums off when calling init()

  6. initdb: Add new option "--no-data-checksums"

  7. Tweak docs to reduce possible impact of data checksums

Re: Heikki Linnakangas
> 1. Have pg_upgrade run initdb for you. It's always felt silly that you need
> to run initdb with the new version yourself, when there's really only one
> correct way to do it.

Fwiw, Debian's pg_upgradecluster script would be happy if that problem
would be solved. Currently, we have to do all sorts of inspection of
the old cluster to figure out the locale used, data checksums, and we
are likely missing some more properties that could carried over (like
wal segment size etc). Some of the info isn't even available from the
control file but needs a connection to the running server.

The problem exists for both the pg_upgrade and dump-restore upgrade
methods, so an "initdb --like /path/to/other/cluster" mode would be
handy to have. Perhaps including a "initdb --like --print-command"
mode.

The pg_{backup,restore}cluster scripts have the same problem. It's
unnecessarily complex to recreate an existing setup.

Maybe it would be enough if the initdb options used to create a
cluster would be stored in some file in the data dir. (Perhaps in a
new line in PG_VERSION? As part of the control file?)

Christoph