On Fri, 3 Oct 2003, Kathy Zhu wrote:
> Hi, > > I notices a weird thing here. > > version 7.2.1 > on Solaris > > table "test", has a field "state". > There are 4 "state" values, 1, 2, 3, 4. > > select count(*) from test group by state; > took 11500 msec > > but > > select count(*) from test where state = 1; > select count(*) from test where state = 2; > select count(*) from test where state = 3; > select count(*) from test where state = 4; > total took 626 msec > I believe Solaris's qsort implementation (which is used for the group by) has problems dealing with large numbers of similar values. I think in later versions of pg our own qsort is used. Kris Jurka ---------------------------(end of broadcast)--------------------------- TIP 4: Don't 'kill -9' the postmaster
