public inbox for [email protected]  

help / color / mirror / Atom feed

From: Daniel Gustafsson <[email protected]>
To: Heikki Linnakangas <[email protected]>
Cc: Tomas Vondra <[email protected]>
Cc: Andres Freund <[email protected]>
Cc: Bernd Helmle <[email protected]>
Cc: Michael Paquier <[email protected]>
Cc: Michael Banck <[email protected]>
Cc: PostgreSQL Hackers <[email protected]>
Subject: Re: Changing the state of data checksums in a running cluster
Date: Thu, 19 Mar 2026 14:49:21 +0100
Message-ID: <[email protected]> (raw)
In-Reply-To: <[email protected]>
References: <[email protected]>
	<[email protected]>
	<[email protected]>
	<[email protected]>
	<[email protected]>
	<[email protected]>
	<[email protected]>
	<[email protected]>
	<[email protected]>
	<[email protected]>
	<5mv5vtbqj2xm2wmevsi22smyn32jtznva3ya3daih3ixh3onex@s5fyab63xt3c>
	<[email protected]>
	<[email protected]>
	<[email protected]>
	<[email protected]>
	<[email protected]>
	<[email protected]>
	<[email protected]>
	<[email protected]>
	<[email protected]>
	<[email protected]>

> On 18 Mar 2026, at 09:06, Heikki Linnakangas <[email protected]> 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

view thread (60+ messages)  latest in thread

reply

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Reply to all the recipients using the --to and --cc options:
  reply via email

  To: [email protected]
  Cc: [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected], [email protected]
  Subject: Re: Changing the state of data checksums in a running cluster
  In-Reply-To: <[email protected]>

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

This inbox is served by agora; see mirroring instructions
for how to clone and mirror all data and code used for this inbox