Thread: WHERE order

It would appear that in 7.4 the order of clauses in WHERE affects the
execution time (not output if AND).

I would think that a simple optimization would be to push off evaluation
of a subplan whenever possible by re-arranging AND statements.

In the below example, it gives an order of magnitude speed increase on a
small dataset.

Rod Taylor <rbt@rbt.ca> writes:
> I would think that a simple optimization would be to push off evaluation
> of a subplan whenever possible by re-arranging AND statements.

Thought we did that already ... [ checks code ] ... hmph, it looks like
this is done correctly for quals attached to a scan node, but not for
quals attached to a join node.  Oops.
        regards, tom lane