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

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... :/

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.


--
Peter Geoghegan