Re: REPACK (CONCURRENTLY) can crash a logical decoding session

On Tue, Sep 8, 2026 at 2:12 PM Masahiko Sawada <sawada(dot)mshk(at)gmail(dot)com> wrote:
>
> On Sun, Sep 6, 2026 at 9:18 AM Zhijie Hou (Fujitsu)
> <houzj(dot)fnst(at)fujitsu(dot)com> wrote:
> >
> > Hi
> >
> > On Saturday, September 5, 2026 3:17 PM Masahiko Sawada <sawada(dot)mshk(at)gmail(dot)com> wrote:
> > > I've attached the updated patches. I merged Antonin's two patches into one
> > > with some cosmetic changes and the 0002 patch fixes issue (2).
> > > Please review them.
> >
> > Both fixes look good to me. Just one question for the 0002.
> >
> > + /*
> > + * Ignore update records without a new tuple. This happens when the
> > + * caller of heap_update() asked for the change not to be decoded, as
> > + * REPACK (CONCURRENTLY) does for the transient heap.
> > + */
> > + if (!(xlrec->flags & XLH_UPDATE_CONTAINS_NEW_TUPLE))
> > + return;
> >
> > It seems to me that updates on catalog relations with no new tuple will also be
> > skipped after this patch. I think that's fine, but perhaps we could mention this
> > case in the comment to make the behavior clearer.
>
> Good point. I've updated the comment accordingly and attached the
> updated patches.
>
> Also, I've fixed a whitespace issue in the 0001 patch.

The patches look good to me so I'm going to push them, barring any objections.

Regards,

--
Masahiko Sawada
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