Re: optimize query with a maximum(date) extraction

[Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>]

Gregory Stark <stark(at)enterprisedb(dot)com> writes:
> You can simulate such a plan with the subqueries I described but
> there's a bit more overhead than necessary and you need a reasonably
> efficient source of the distinct ids.

Yeah, that seems like the $64 question.  If you have no better way of
finding out the set of ID values than a seqscan, then there's no point
in trying to optimize the min/max accumulation ...

			regards, tom lane