[postgis-users] GIST index speed

Markus Schaber schabi at logix-tt.com
Thu Jun 5 02:34:38 PDT 2008

Hi, Paul,

"Paul Ramsey" <pramsey at cleverelephant.ca> wrote:

> First, basic index concepts: when you are requesting the whole data
> set, the index (any index) does *nothing* for your performance.  To
> use an (obsolete) metaphor, if you are checking out *every* book in
> the library, do you first go to the card catalog?
> So your test case isn't testing anything index related.

Acutally, when most geometries do not even touch the bounding box of
his given query geometry, an index could speed up the whole query.


Markus Schaber | Logical Tracking&Tracing International AG
Dipl. Inf.     | Software Development GIS

Fight against software patents in Europe! www.ffii.org

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