Greg Stark <gsstark(at)mit(dot)edu> writes:
> So one of the items on the TODO list is "Add hash for evaluating GROUP BY
> aggregates (Tom)"
It's done in CVS tip ... give it a try.
> The neat thing is that hash aggregates would allow grouping on data types that
> have = operators but no useful < operator.
Hm. Right now I think that would barf on you, because the parser wants
to find the '<' operator to label the grouping column with, even if the
planner later decides not to use it. It'd take some redesign of the
query data structure (specifically SortClause/GroupClause) to avoid that.
regards, tom lane