Alvaro Herrera <[EMAIL PROTECTED]> writes: > What about having a new column in pg_aggregate which would point to a > function that would try to optimize the aggregate's handling?
I can't get very excited about this, because how would you make a reasonably stable/narrow API for such a thing? The function as you propose it would have to know everything about not only the planner's data representations but the N specific places it would be called from. The existing selectivity functions are bad enough on this score ... regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 8: explain analyze is your friend