[postgis-users] && operator memory leak

Mark Cave-Ayland m.cave-ayland at webbased.co.uk
Mon Mar 8 03:13:59 PST 2004

> -----Original Message-----
> From: postgis-users-bounces at postgis.refractions.net 
> [mailto:postgis-users-bounces at postgis.refractions.net] On 
> Behalf Of Carl Anderson
> Sent: 08 March 2004 02:27
> To: postgis-users at postgis.refractions.net
> Subject: [postgis-users] && operator memory leak
> Is anyone actively working on the memory leak in the gist && 
> operator. Or can anyone give me a heads up start point?
> I have had enough of partitioning queries to work around an out ouf  
> memory condition and willing to delve into this issue.
> the issue manifests most simply with a gist index on the_geom 
> for both  
> tables and
> select 1 from mytab
>    where
>      exists ( select 1
>                 from othertab
>                   where othertab.the_geom && mytab.the_geom
>             );
> with
>    mytab ~ 100 thousand tuples
> and
>    othertab ~ 1 million tuples
> much more than 3Gb of real memory is required during the query.
> my datasets have much more than 1 million tuples.
> C.

Hi Carl,

Please can you give us some more information? In particular we would
need the versions of PostgreSQL, PostGIS that you are using, plus the
EXPLAIN ANALYZE output of both:

select 1 from othertab where othertab.the_geom && mytab.the_geom


select 1 from mytab where exists 
	(select 1 from othertab where othertab.the_geom &&

(NOTE: If the memory leak prevents an EXPLAIN ANALYZE from running the
second query then just an EXPLAIN will hopefully get things moving in
the right direction)




Mark Cave-Ayland
Webbased Ltd.
Tamar Science Park

Tel: +44 (0)1752 764445
Fax: +44 (0)1752 764446

This email and any attachments are confidential to the intended
recipient and may also be privileged. If you are not the intended
recipient please delete it from your system and notify the sender. You
should not copy it or use it for any purpose nor disclose or distribute
its contents to any other person.

More information about the postgis-users mailing list