On Mon, Jan 26, 2009 at 1:58 PM, Filip Rembiałkowski <plk.zu...@gmail.com> wrote: > 2009/1/26 Grzegorz Jaśkiewicz <gryz...@gmail.com> >> >> Hey folks, >> >> I have question really for all mighty developers, but don't want to >> spam -hackers with it. >> >> why : >> select * from foo where X in (1,1,1,1,1,1,1,1) --- same values in search. >> or select * from foo where (x,y) in >> ((1,2),(1,2),(1,2),(1,2),(1,2),(1,2),(1,2)); >> >> never gets optimized by planner, etc ? > > I would guess that optimizing silly-written queries was always a > low-priority task...
> EXPLAIN ANALYZE SELECT * FROM atest where id in > (1,2,3,3,3,3,3,3,3,5,5,5,5,5,5,5,5,5,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1); > EXPLAIN ANALYZE SELECT * FROM atest where id in (1,2,3,5); > > shows that second query is 2.5 times faster than the first ( 0.170 ms / > 0.070 ms). the difference isn't so small than :) silly or not, sometimes you end up with such collection passed on in some silly languages. -- GJ -- Sent via pgsql-general mailing list (pgsql-general@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
