Re: Enable data checksums by default

Alvaro Herrera <alvherre@alvh.no-ip.org>

From: Alvaro Herrera <alvherre@alvh.no-ip.org>

To: Peter Eisentraut <peter@eisentraut.org>

Cc: Greg Sabino Mullane <htamfids@gmail.com>, pgsql-hackers <pgsql-hackers@postgresql.org>

Date: 2024-11-13T11:03:05Z

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 2024-Nov-13, Peter Eisentraut wrote:

> On 07.11.24 19:38, Alvaro Herrera wrote:
> > I have just noticed that since this patch was committed as 04bec894a04c,
> > pg_upgrade's "make check" action is unusable when given the
> > "olddump/oldinstall" options.  We now need to inject '-k' to the initdb
> > line for old servers, and we don't, so all upgrade tests fail.  I think
> > this patch should be enough to fix it.
> 
> Yes, this fix looks correct.

Thanks, pushed.

> (Or the other way around: Disable checksums on the new node.)

Yeah, I thought about that too, but, I think it'd be less realistic,
because the world is become one where checksums are enabled, not the
other way around.

> Is this not being covered by the build farm?  Are the upgrade tests there
> not using this?

Nope, the buildfarm has separate code to test cross-version upgrades,
https://github.com/PGBuildFarm/client-code/blob/main/PGBuild/Modules/TestUpgradeXversion.pm
This predates our in-core test support.  Maybe buildfarm's could be
simplified, but I'm not sure if it's worth it.

-- 
Álvaro Herrera         PostgreSQL Developer  —  https://www.EnterpriseDB.com/
"El sentido de las cosas no viene de las cosas, sino de
las inteligencias que las aplican a sus problemas diarios
en busca del progreso." (Ernesto Hernández-Novich)