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help / color / mirror / Atom feedFrom: Andres Freund <[email protected]>
To: Antonin Houska <[email protected]>
Cc: Mihail Nikalayeu <[email protected]>
Cc: Amit Kapila <[email protected]>
Cc: Alvaro Herrera <[email protected]>
Cc: Srinath Reddy Sadipiralla <[email protected]>
Cc: Matthias van de Meent <[email protected]>
Cc: Pg Hackers <[email protected]>
Cc: Robert Treat <[email protected]>
Subject: Re: Adding REPACK [concurrently]
Date: Tue, 14 Apr 2026 09:58:55 -0400
Message-ID: <aixbxaenmbvsaarnxpagkgajv25zpc4ogo6gwv7lr7bbrh3arp@xom2lyvdgccf> (raw)
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Hi,
On 2026-04-14 15:37:56 +0200, Antonin Houska wrote:
> Andres Freund <[email protected]> wrote:
>
> > On 2026-04-12 15:31:20 +0200, Mihail Nikalayeu wrote:
> > > Instead of cancelling the backend entered the deadlock detector - it
> > > cancel some another (nearest hard edge) until it is possible to get the
> > > lock (either by
> > > reordering or directly).
> >
> > I don't think that's as good. The problem is that that way you're only
> > detecting the deadlocks once they have materialized (i.e. once repack actually
> > does the lock upgrade), rather than cancelling when we know that the problem
> > starts.
>
> This is my hack that tries to do that.
I still think this needs to be in the deadlock detector. The lock cycle just
needs to be a bit more complicated for a hack in JoinWaitQueue not to work.
There's no guarantee that the wait that triggers the deadlock is actually on
the relation being repacked.
Greetings,
Andres Freund
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Subject: Re: Adding REPACK [concurrently]
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