On Tue, 19 Oct 2004, Sailesh Krishnamurthy wrote: > >>>>> "Tom" == Tom Lane <[EMAIL PROTECTED]> writes: > > Tom> One huge advantage is that the actual heap visiting becomes > Tom> efficient, eg you never visit the same page more than once. > Tom> (What you lose is the ability to retrieve data in index > Tom> order, so this isn't a replacement for existing indexscan > Tom> methods, just another plan type to consider.) > > Even without bitmap indexes, without trying to use multiple indexes > etc. this (visiting a page only once) is useful. > > In other words, I'd like to see the indexscan broken up into: (1) an > operator that returns a list of TIDs, (2) Sort the TIDs and (3) an > operator that fetches heap tuples from the sorted TID list.
I'm uncertain about the potential benefit of this. Isn't/shouldn't the effects of caching be assisting us here? Gavin ---------------------------(end of broadcast)--------------------------- TIP 4: Don't 'kill -9' the postmaster
