Pavel Hlavnicka <pavel(at)gingerall(dot)cz> writes:
> select * from foo
> where created_at >= 'now'::timestamp - '1 hour'::interval;
> My table is indexed on created_at field. The query above doesn't use it,
What's your PG version? In 7.2 and later that expression will be folded
to a constant.
regards, tom lane