Re: Berserk Autovacuum (let's save next Mandrill)

I wrote:
> Dean Rasheed <dean.a.rasheed@gmail.com> writes:
>> I had a go at reproducing this. I wasn't able to produce the reported
>> failure, but I can reliably produce an Assert failure that may be
>> related by doing a VACUUM FULL simultaneously with an ANALYZE that is
>> generating extended stats, which produces:
>> ...
>> It looks to me as though the problem is that statext_store() needs to
>> take its lock on pg_statistic_ext_data *before* searching for the
>> stats tuple to update.

> Hmm, yeah, that seems like clearly a bad idea.

I pushed a fix for that, but I think it must be unrelated to the
buildfarm failures we're seeing.  For that coding to be a problem,
it would have to run concurrently with a VACUUM FULL or CLUSTER
on pg_statistic_ext_data (which would give all the tuples new TIDs).
AFAICS that won't happen with the tests that are giving trouble.

            regards, tom lane