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 har�n por las perlas,
�Y las de Arrakis por el agua! Pero si buscas damas
Que se consuman como llamas, �Prueba una hija de Caladan! (Gurney Halleck)
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