Re: [HACKERS] pg_upgrade to clusters with a different WAL segment size

On 2017-11-14 07:26:22 +0900, Michael Paquier wrote:
> On Tue, Nov 14, 2017 at 6:11 AM, Andres Freund <andres(at)anarazel(dot)de> wrote:
> > Hm. I'm not really on-board with doing this in pg_upgrade. A more
> > logical place seems to be pg_resetwal or something - there's no need to
> > force a pg_upgrade cycle (which is pretty expensive on clusters with a
> > significant number of objects) for somebody that wants to change the
> > segment size of a cluster without changing the major version.
> > pg_resetwal or a new tool seems like a more appropriate places for this.
>
> pg_upgrade makes use of pg_resetwal, so I am assuming that what Nathan
> means is actually what you mean, so as pg_upgrade gains as well an
> option with the segment size which will wrap the pg_resetwal's call.

Even if that's the case, I fail to see why it'd be a good idea to have
any sort of pg_upgrade integration here. We should make pg_resetwal's
checks for this good enough, and not conflate something unrelated with
pg_upgrade goals.

Greetings,

Andres Freund