On Thu, 2006-05-11 at 12:18, Jim C. Nasby wrote: > On Wed, May 10, 2006 at 08:31:54PM -0400, Tom Lane wrote: > > "Jim C. Nasby" <jnasby@xxxxxxxxxxxxx> writes: > > > On Tue, May 09, 2006 at 03:13:01PM -0400, Tom Lane wrote: > > >> PFC <lists@xxxxxxxxxx> writes: > > >>> Fun thing is, the rowcount from a temp table (which is the problem here) > > >>> should be available without ANALYZE ; as the temp table is not concurrent, > > >>> it would be simple to inc/decrement a counter on INSERT/DELETE... > > >> > > >> No, because MVCC rules still apply. > > > > > But can anything ever see more than one version of what's in the table? > > > > Yes, because there can be more than one active snapshot within a single > > transaction (think about volatile functions in particular). > > Any documentation on how snapshot's work? They're a big mystery to me. > :( http://www.postgresql.org/docs/8.1/interactive/mvcc.html Does the concurrency doc not cover this subject well enough (I'm not being sarcastic, it's a real question)
