On Tue, Nov 18, 2003 at 02:31:03PM -0800, Sailesh Krishnamurthy wrote: > Another thing I toyed with was having an implementation of a > Tid-List-Fetch .. sorting a TID-list from an index and fetching the > records of the relation off the sorted list for better IO > performance. AFAICT something like this isn't present yet .. can pgsql > do this already ?
Nope. In fact it's on the TODO list. I think people call it "bitmap indexes", the idea being that the TID list is represented as a "sparse bitmap" (go ask some JPEG hacker what that means). Extra points if multiple bitmaps can be ANDed and ORed, to allow using multiple indexes simultaneously ... -- Alvaro Herrera (<alvherre[a]dcc.uchile.cl>) Oh, oh, las chicas galacianas, lo harán por las perlas, ˇY las de Arrakis por el agua! Pero si buscas damas Que se consuman como llamas, ˇPrueba una hija de Caladan! (Gurney Halleck) ---------------------------(end of broadcast)--------------------------- TIP 5: Have you checked our extensive FAQ? http://www.postgresql.org/docs/faqs/FAQ.html