[postgis-users] looking for some perf data

raphael Jacquot sxpert at sxpert.org
Tue Nov 21 09:14:44 PST 2006

Martin Davis wrote:
> First of all, you need to be more specific.  The performance of an index 
> is related to the kinds of queries you are making on it.   If you are 
> making  a simple equality query, then a B-tree on the (x,y) pair is 
> probably fine.  But if you're wanting to do range searches in two 
> dimensions, a B-tree does not support this kind of query, and hence 
> performance will be slow compared to an access method which does support 
> this (e.g. R-tree, quad-tree, etc etc).

typically I'm looking to compare using

create table blah1 (
	lon	double precision,
	lat	double precision
with one index on lon and another one on lat

the classic request being
lon>constant1 and lon<constant2 and lat>constant3 and lat<constant4


create table blah2 (
	position Point
with a gist r-tree index

using the @ operator

> raphael Jacquot wrote:
>> hi there
>> I'm looking for some hard verifiable proof that using r-tree based 
>> geometry indexes is better than using 2 columns and a btree index on 
>> it, performance wise.
>> has there any study done on that ?
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