Re: Changing the state of data checksums in a running cluster

> On 18 Mar 2026, at 09:06, Heikki Linnakangas <hlinnaka(at)iki(dot)fi> wrote:
> On 18/03/2026 00:01, Daniel Gustafsson wrote:

>>> What if a database is dropped and another one is created with the same database OID?
>> Good point. We have the name of the database so we could compare Oid and name,
>> and require both to match. That would still be foiled by a new database using
>> the same Oid and name though. Any ideas on what could be done?
> Well, if CREATE DATABASE computed the checksums, that would fix this too. Actually, at least in the default wal_log=true mode, doesn't it already do that? It goes through the buffer cache as usual, I presume the checksums will be computed too.

That's a very good point, if the CREATE DATABASE is issued with wal_log and not
file_copy it will mark the buffers dirty during copying which will calculate
and set the checkpoint. If file_copy isn't allowed during inprogress-on then
the logic around rescanning databases for new entries could be quite
simplified.

--
Daniel Gustafsson