On Wed, Jan 03, 2007 at 11:56:20AM -0500, Tom Lane wrote: > Erik Jones <erik@xxxxxxxxxx> writes: > > Tom Lane wrote: > >> I could see this taking an unreasonable amount of time if you had a huge > >> number of pg_class rows or a very long search_path --- is your database > >> at all out of the ordinary in those ways? > >> > > Well, running "select count(*) from pg_class;" returns 524699 rows > > Ouch. > > > our search path is the default. I'd also like to reiterate that \d > > pg_class returns instantly when run from the 8.1.4 psql client connected > > to the 8.2 db. > > I think I know where the problem is: would you compare timing of > > select * from pg_class where c.relname ~ '^(pg_class)$'; > > select * from pg_class where c.relname ~ '^pg_class$'; > > Recent versions of psql put parentheses into the regex pattern for > safety in case it's got "|", but I just realized that that probably > confuses the optimizer's check for an indexable regex :-( > > However, this only explains slowdown in psql's \d commands, which > wasn't your original complaint ... On the other hand, with 500k relations pg_dump is presumably going to be doing a lot of querying of the catalog tables, so if it uses similar queries... -- Jim Nasby jim@xxxxxxxxx EnterpriseDB http://enterprisedb.com 512.569.9461 (cell)
