Horton

Re: Enable data checksums by default

Tomas Vondra <tomas@vondra.me>

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From: Tomas Vondra <tomas@vondra.me>
To: 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: 2025-08-19T12:22:06Z
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

On 7/29/25 20:24, Tomas Vondra wrote:
> Hi!
> 
> 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.
> 
> We don't have a strong opinion either way, but there doesn't seem to be
> much happening on this thread. So if someone feels we should rethink and
> disable the checksums by default for PG18, he/she needs to articulate
> that proposal. The sooner the better.
> 
> The commit that flipped the default (04bec894a04c) is from Peter
> Eisentraut, and while that doesn't make him solely responsible for the
> change, we think it'd be good to know his opinion on this. But it seems
> more like a change requiring a wider consensus, and I'm aware e.g.
> Andres expressed some doubts about enabling checksums [2].
> 
> In any case, the default is "on" at the moment, and unless someone
> advocates for changing it soon, that's what we'll get in PG19.
> 

I've moved the item to the "resolved before rc1" section.

Given the recent inactivity on this thread, and lack of proposals to
change the default for PG18 (to disable checksums by default), I think
we're going to keep the current default.

We may rethink, but there's not much time to consider such proposal.


regards

-- 
Tomas Vondra