Re: BUG #17255: Server crashes in index_delete_sort_cmp() due to race condition with vacuum

On 2022-01-12 13:05:45 -0800, Peter Geoghegan wrote:
> On Wed, Jan 12, 2022 at 11:25 AM Andres Freund <andres@anarazel.de> wrote:
> > > Any blockers?
> >
> > I'm just struggling with / procrastinating on the commit message, tbh. The
> > whole issue is kinda complicated to explain... :/

After struggling some more, I *finally* pushed the fix and the new assertions.


Thanks for the bug report, investigation, review, etc!


> I think that it would make sense for the commit message to frame the
> problem as: pruneheap.c doesn't take sufficient care when traversing
> HOT chains to determine their full extent, for the purposes of
> pruning. There was a general lack of robustness, and the snapshot
> scalability work happened to run into that, resulting in hot chain
> corruption under very specific conditions.
>
> If I was in your position I think I would resist framing the problem
> in this way; I'd probably be concerned that it would come off as
> shifting the blame elsewhere. This high level explanation of things
> makes the most sense to me, though. Surely that's the most important
> thing.

Thanks!