Jeff Davis <[EMAIL PROTECTED]> writes: > We can already keep stats for a functional index. Is there a reason we > can't keep stats for a multi-column index?
The questions that need to be answered are (1) what stats are you gonna collect, and (2) exactly what are you going to do with them when you have 'em? All the previous discussions have stalled on the question of how to avoid trying to collect stats about an exponentially large number of column combinations; we've never even reached the question of what stats we'd actually want given that a particular combination has been determined to be interesting. Perhaps that's a trivial question, but it's been a mighty long time since I took statistics ... regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 2: Don't 'kill -9' the postmaster