Re: pg_autovacuum crashes when query fails for temp

matthew@zeut.net ("Matthew T. O'Connor") wrote:
>> Bruce Momjian wrote:
>> Should pg_autovacuum be vacuuming temporary tables?
>
> This is a good question, and I would like some opinions from some other
> people more informed than I.
>
>> Secondly, why would
>> a temporary table for another session be visible to pg_autovacuum?  I
>> know these may sound like stupid questions, but I'm a little shocked
>> that it found a temp table.  Did someone make a permanent table, delete
>> it, and pg_autovacuum found it in between those operations?
>
> I will look into this when I have time, it certainly would be possible
> that pg_autovacuum could be tripped up by a sequence of events like you
> describe above.  The more general problem is that it shouldn't crash even
> if it's vacuuming tables it shouldn't.

Well, there's an entry in pg_class even for temporary tables; that
means that even though a separate session has no ability to vacuum the
table, there is still a way to get at its name.

I would think that temp tables are TERRIBLE candidates for
auto-vacuuming; they are likely to be created via INSERT or SELECT
INTO, and if there is a need to analyze such a table, it is likely
needful to do so under strict application control.
-- 
let name="cbbrowne" and tld="acm.org" in String.concat "@" [name;tld];;
http://www3.sympatico.ca/cbbrowne/advocacy.html
Rules of  the Evil Overlord #196.  "I will hire an  expert marksman to
stand by the entrance to my  fortress. His job will be to shoot anyone
who rides up to challenge me."  <http://www.eviloverlord.com/>