Tom, > Raising work_mem to a gig should result in about five runs, needing only > one pass, which is really going to be as good as it gets. If you could > not see any difference then I see little hope for the idea that reducing > the number of merge passes will help.
Right. It *should have*, but didn't seem to. Example of a simple sort test of 100 million random-number records 1M 3294 seconds 16M 1107 seconds 256M 1209 seconds 512M 1174 seconds 512M with 'not null' for column that is indexed 1168 seconds > Umm ... you were raising maintenance_work_mem, I trust, not work_mem? Yes. > > We really need to get some hard data about what's going on here. The > sort code doesn't report any internal statistics at the moment, but it > would not be hard to whack together a patch that reports useful info > in the form of NOTICE messages or some such. Yeah, I'll do this as soon as the patch is finished. Always useful to gear up the old TPC-H. -- --Josh Josh Berkus Aglio Database Solutions San Francisco ---------------------------(end of broadcast)--------------------------- TIP 2: Don't 'kill -9' the postmaster
