Re: pg_waldump and PREPARE

On Thu, Jul 4, 2019 at 9:45 AM Michael Paquier <michael(at)paquier(dot)xyz> wrote:
>
> On Wed, Jul 03, 2019 at 08:23:44PM +0200, Julien Rouhaud wrote:
> > So the patch compiles and works as intended. I don't have much to say
> > about it, it all looks good to me, since the concerns about xactdesc.c
> > aren't worth the trouble.
> >
> > I'm not sure that I understand Michael's objection though, as
> > xl_xact_prepare is not a new definition and AFAICS it couldn't contain
> > the records anyway. So I'll let him say if he has further objections
> > or if it's ready for committer!
>
> This patch provides parsing information only for the header of the 2PC
> record. Wouldn't it be interesting to get more information from the
> various TwoPhaseRecordOnDisk's callbacks? We could also print much
> more information in xact_desc_prepare(). Like the subxacts, the XID,
> the invalidation messages and the delete-on-abort/commit rels.

Most of those are already described in the COMMIT PREPARE message,
wouldn't that be redundant? abortrels aren't displayed anywhere
though, so +1 for adding them.

I also see that the dbid isn't displayed in any of the 2PC message,
that'd be useful to have it directly instead of looking for it in
other messages for the same transaction.