On Mon, 30 Aug 2004, Martin Sarsale wrote: > On Mon, 2004-08-30 at 15:06, Merlin Moncure wrote: > > create function is_somethingable (ctype, dtype) returns boolean as > > Thanks, but I would prefer a simpler solution. > > I would like to know why this uses a seqscan instead of an index scan: > > create index t_idx on t((c+d)); > select * from t where c+d > 0;
As a geuss, since 7.4 and earlier have no statistics on the distribution of c+d it has to guess about how likely that is to be true and is probably overestimating. 8.0beta might handle this better. ---------------------------(end of broadcast)--------------------------- TIP 1: subscribe and unsubscribe commands go to [EMAIL PROTECTED]
