"Davor J." <DavorJ@live.com> writes:
> Now, if one takes a subquery for "1", the optimizer evaluates it first
> (let's say to "1"), but then searches for it (sequentially) in every
> partition, which, for large partitions, can be very time-consuming and goes
> beyond the point of partitioning.
No, the optimizer doesn't "evaluate it first". Subqueries aren't ever
assumed to reduce to constants. (If you actually do have a constant
expression, why don't you just leave out the word SELECT?)
regards, tom lane
