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<TITLE>RE: [postgis-users] st_within too slow?</TITLE>
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<P><FONT SIZE=2>Pedro,<BR>
<BR>
Try using st_intersects instead of ST_within. In general I think it performs better than within and for point in poly will be just as good.<BR>
<BR>
Yah Guido's suggestion would be at best give same timing since ST_Within, ST_Intersects have an implicit && call in them so they can limit the number of more painful _ST_Within, _ST_Intersects checks they actually need to do.<BR>
<BR>
Hope that helps,<BR>
Regina<BR>
<BR>
<BR>
<BR>
-----Original Message-----<BR>
From: postgis-users-bounces@postgis.refractions.net on behalf of Pedro Doria Meunier<BR>
Sent: Sat 8/30/2008 8:16 AM<BR>
To: PostGIS Users Discussion<BR>
Subject: RE: [postgis-users] st_within too slow?<BR>
<BR>
Dear Guido,<BR>
<BR>
Thanks for replying.<BR>
Your suggested mod actually worsens the performance by another ~15-20ms<BR>
<BR>
Best regards,<BR>
--<BR>
Pedro Doria Meunier <pdoria@netmadeira.com><BR>
<BR>
> Pedro,<BR>
><BR>
> Try this instead:<BR>
><BR>
> SELECT road_network, toponymy FROM maps AS m WHERE m.b_box &&<BR>
> geomfromtext('POINT($lon $lat)',4326) and<BR>
> st_within(geomfromtext('POINT($lon $lat)',4326), m.b_box)<BR>
><BR>
> of course, if you already know that the point is in Portugal,<BR>
> you could do:<BR>
><BR>
> SELECT road_network, toponymy FROM maps AS m WHERE<BR>
> m.country = 'PT' and<BR>
> m.b_box && geomfromtext('POINT($lon $lat)',4326)<BR>
><BR>
> (assuming that the maps table has the 'country' column with<BR>
> country names).<BR>
><BR>
> GL<BR>
<BR>
<BR>
</FONT>
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