Am Donnerstag, 22. März 2007 16:17 schrieb Andreas Kostyrka: > * Mario Weilguni <mweilguni@xxxxxxxx> [070322 15:59]: > > Am Donnerstag, 22. März 2007 15:33 schrieb Jonah H. Harris: > > > On 3/22/07, Merlin Moncure <mmoncure@xxxxxxxxx> wrote: > > > > As others suggest select count(*) from table is very special case > > > > which non-mvcc databases can optimize for. > > > > > > Well, other MVCC database still do it faster than we do. However, I > > > think we'll be able to use the dead space map for speeding this up a > > > bit wouldn't we? > > > > Which MVCC DB do you mean? Just curious... > > Well, mysql claims InnoDB to be mvcc ;) Ok, but last time I tried count(*) with InnoDB tables did take roughly(*) the same time last time I tried - because InnoDB has the same problem as postgres and has to do a seqscan too (I think it's mentioned somewhere in their docs). (*) in fact, postgres was faster, but the values were comparable, 40 seconds vs. 48 seconds Maybe the InnoDB have made some progress here, I tested it with MySQL 5.0.18.
