[postgis-devel] Re: [postgis-users] GIST index speed

[Tom Lane]

Mark Cave-Ayland <mark.cave-ayland at siriusit.co.uk> writes:
> postgis=# explain analyze select count(*) from geography a join 
> geography b on (b.the_geom &&
> b.centroid) where a.id = 69495;

Is that query really meaningful?  You seem to be forming the
cartesian product of a subset of a with an unrelated subset of b.

			regards, tom lane