[postgis-devel] optimized predicates
pramsey at cleverelephant.ca
Thu Jul 10 16:10:59 PDT 2008
GEOS trunk (which carries a version number of 3.1) includes the
prepared methods, and if PostGIS detects that version, it will use
them. This seemed like a safe thing at the time, since GEOS 3.1 is not
released, you have to use the SVN version to get it.
Kevin is seeing the same thing I reported earlier:
I was hoping Ben would be able to attack this before it became
something anyone else noticed.
On Thu, Jul 10, 2008 at 4:06 PM, Paul Ramsey <pramsey at cleverelephant.ca> wrote:
> On Thu, Jul 10, 2008 at 1:34 PM, Martin Davis <mbdavis at refractions.net> wrote:
>> Are we correct in thinking that GEOS 3.1 uses the PreparedGeometry
>> predicates to implement ST_Contains and ST_Intersects?
>> If so, perhaps it would be better to revert to the original implementation
>> for these predicates, and provide different function names for the Prepared
>> versions, until this problem is fixed?
>> Kevin Neufeld wrote:
>>> Hi folks, there seems to be a significant memory leak issue with
>>> ST_Contains() and ST_Intersects().
>>> I'm trying to do a simple point-in-polygon join using ~800 points and
>>> ~250000 polygons.
>>> Running PG8.3.3, PGIS1.3.3, and GEOS="3.1.0-CAPI-1.5.0", the query spikes
>>> up to 3GB of RAM before completing in 20seconds.
>>> Running PG8.2.0, PGIS1.1.6, the query uses a nominal amount of memory
>>> (indeterminable looking at top), and also runs in 20secs.
>>> -- Kevin
>>> postgis-devel mailing list
>>> postgis-devel at postgis.refractions.net
>> Martin Davis
>> Senior Technical Architect
>> Refractions Research, Inc.
>> (250) 383-3022
>> postgis-devel mailing list
>> postgis-devel at postgis.refractions.net
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