On Mon, 2003-09-08 at 11:56, scott.marlowe wrote: > Basically, Postgresql uses an MVCC locking system that makes massively > parallel operation possible, but costs in certain areas, and one of those > areas is aggregate performance over large sets. MVCC makes it very hard > to optimize all but the simplest of aggregates, and even those > optimzations which are possible would wind up being quite ugly at the > parser level.
As was pointed out in a thread a couple days ago, MIN/MAX() optimization has absolutely nothing to do with MVCC. It does, however, make optimizing COUNT() more difficult. -Neil ---------------------------(end of broadcast)--------------------------- TIP 8: explain analyze is your friend
