On Fri, Nov 9, 2012 at 10:08 AM, Alvaro Herrera <alvhe...@2ndquadrant.com> wrote: > Tom Lane escribió: >> Robert Haas <robertmh...@gmail.com> writes: > >> > IIRC the queue has 4K entries, and IIRC a single DDL >> > operation might provoke a couple of sinvals, but I'm thinking that >> > somebody would probably have to be creating >1024 temp tables a minute >> > to overrun the queue, which is very possible but not necessarily >> > common. >> >> Well, one DDL typically generates multiple messages --- one for each >> catalog row added/modified/removed, roughly speaking. When I run the >> constant create/drop example Jeff posted, I see the AV launcher getting >> a catchup signal every few seconds. I didn't try to determine exactly >> how many create/drop cycles that was, but I'm pretty sure it's a lot >> less than 1000. > > Just creating the sequence for the serial column means 16 pg_attribute > tuples. There's also two pg_class entries, one more pg_attribute, two > pg_type entries, a bunch of pg_depend entries ... I doubt it's less than > 30 catalog tuples, all things considered. Double that for the drop. So > for a 4k entry table that needs to get 50% full, that's only ~35 temp > table creations like that. > > I hadn't realized sequences used so many pg_attribute entries.
Hmm. So, are we going to force a minor release for this, or do we think it's not serious enough to warrant that? I'm not expressing an opinion either way, just asking. -- Robert Haas EnterpriseDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
