Anagh Lal <[EMAIL PROTECTED]> writes: > Why do we not just store the attributes required in > the join (i.e. those in the join qual conditions and > the ones in the select list) and then perform sorting > and retrieval on these tuples rather than on the > possibly larger tuples with more attributes which we > project out in the end anyway.
We already do --- the scan nodes project out only the needed columns. At least, that's true in released versions. Just a few days ago I put a hack into CVS tip to skip the projection step for a scan node that's not topmost in the plan. As you indicate, that's probably a net loss when there's a Sort node directly above the scan node. Needs more thought... regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 1: subscribe and unsubscribe commands go to [EMAIL PROTECTED]