Re: Enable data checksums by default

Nathan Bossart <nathandbossart@gmail.com>

From: Nathan Bossart <nathandbossart@gmail.com>

To: Peter Eisentraut <peter@eisentraut.org>

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: 2024-08-27T15:26:59Z

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, Aug 27, 2024 at 05:16:51PM +0200, Peter Eisentraut wrote:
> On 27.08.24 15:44, Greg Sabino Mullane wrote:
>> On Mon, Aug 26, 2024 at 3:46 PM Nathan Bossart <nathandbossart@gmail.com
>> <mailto:nathandbossart@gmail.com>> wrote:
>> 
>>     Should we error if both --data-checksum and --no-data-checksums are
>>     specified?  IIUC with 0001, we'll use whichever is specified last.
>> 
>> 
>> Hmmm, that is a good question. We have never (to my recollection)
>> flipped a default quite like this before. I'm inclined to leave it as
>> "last one wins", as I can see automated systems appending their desired
>> selection to the end of the arg list, and expecting it to work.
> 
> Yes, last option wins is the normal expected behavior.

WFM

001_verify_heapam fails with this patch set.  I think you may need to use
--no-data-checksums in that test, too.  Otherwise, it looks pretty good to
me.

-- 
nathan