On Mon, May 22, 2006 at 10:23:28 +0200, Albe Laurenz <[EMAIL PROTECTED]> wrote: > > In order to (efficiently) process a GROUP BY clause, you need a > total ordering on the data type that you group by, i.e. an ordering > such that for any two data x and y you have either x < y or x > x > or x = y.
An equality operator is good enough if the number of unique groups isn't too large, so that a hash aggregate plan works efficiently. ---------------------------(end of broadcast)--------------------------- TIP 2: Don't 'kill -9' the postmaster
