Re: Enable data checksums by default

Laurenz Albe <laurenz.albe@cybertec.at>

From: Laurenz Albe <laurenz.albe@cybertec.at>

To: Tomas Vondra <tomas@vondra.me>, Peter Eisentraut <peter@eisentraut.org>, Heikki Linnakangas <hlinnaka@iki.fi>, Nathan Bossart <nathandbossart@gmail.com>

Cc: 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: 2025-07-30T09:58:45Z

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 →

Avoid BufferGetLSNAtomic() calls during nbtree scans.
- e6eed40e4441 18.0 cited
doc PG 18 relnotes: Add incompatibility note about checksums now default
- 48814415d5aa 18.0 landed
Fix pg_upgrade's cross-version tests when old < 18
- 38c18710b37a 18.0 landed
initdb: Change default to using data checksums.
- 04bec894a04c 18.0 landed
Allow TAP tests to force checksums off when calling init()
- e7d0cf42b1ac 18.0 landed
initdb: Add new option "--no-data-checksums"
- 983a588e0b86 18.0 landed
Tweak docs to reduce possible impact of data checksums
- efd72a3d422b 18.0 landed

On Tue, 2025-07-29 at 20:24 +0200, Tomas Vondra wrote:
> So, what should we do with the PG18 open item? We (the RMT team) would
> like to know if we shall keep the checksums enabled by default, and if
> there's something that still needs to be done for PG18.

I don't have a strong opinion, but I lean towards having them on
by default.  Yes, that has a performance impact (e.g. WAL logging hints),
and people with reliable storage may be better off disabling checksums.
But I think it is better to set the default values so that they are
good for those people who don't have a lot of PostgreSQL knowledge and
are running less demanding installations on mediocre hardware.

Yours,
Laurenz Albe