Re: BUG #17372: Altering statistics during concurrent drop can lead to a server crash

Hello Tomas,
20.01.2022 20:57, Tomas Vondra wrote:
> Thanks for the report - I've reproduced it using your script (I had to
> add a short wait before the syscache lookup). The issue is fairly
> simple, we never check we actually found a tuple in the syscache, i.e.
> there's no HeapTupleIsValid() call. We check the OID earlier, but the
> tuple may have disappeared since then.
>
> IMO the usual "cache lookup failed" error that we throw in other places
> in similar cases is good enough. We already fail with other errors
> (tuple concurrently updated/deleted) here.
Yes, the rough, but simple search:
grep -Porz
'.*=\s*SearchSysCache1.*\n(?!(.*|.*\n.*|.*\n.*\n.*|.*\n.*\n.*\n.*)HeapTupleIsValid)'
./
finds only this place.
Your fix works for me.

Thanks!

Best regards,
Alexander