"Simon Riggs" <[EMAIL PROTECTED]> writes: >> Tom Lane writes >> In particular, the optimization paths that involve unique-ifying the >> subselect output and then using it as the outer side of a join would >> definitely not work for these sorts of things.
> I'm not sure if I've understood you correctly in the section above. Are > you saying that these types of queries don't have a meaningful or > defined response? Or just that they wouldn't be very well optimized as a > result of the unique-ifying code changes? I mean that if the unique-ifying implementation were used, it'd deliver the wrong answer (too many rows out). You could possibly carry through a set of extensions to check which kind of sub-SELECT was in use and not apply transformations that aren't correct, but it'd be a great deal more complexity for something of marginal value. As far as I've seen, people don't use inequalities in ANY/ALL subselects very much, and so I'm not excited about complicating the planner to support them better. regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 4: Don't 'kill -9' the postmaster