[postgis-users] about range query

[Paragon Corporation]

http://www.postgis.org/documentation/manual-svn/ST_DWithin.html



  _____  

From: postgis-users-bounces at postgis.refractions.net
[mailto:postgis-users-bounces at postgis.refractions.net] On Behalf Of
superman0920
Sent: Friday, May 04, 2012 10:11 PM
To: postgis-users
Subject: [postgis-users] about range query


hi
I have over 8500000 records in the postgresql and every record has a geom
column what is store a point.
I get a point coordinate(eg 116.1124,39.9046 ) and I want to know the
coordinates of db points which is in 500m range.
 
I use 
ST_Distance(
the_geom,
'srid=4326;point(116.1124 39.9046)'
) <= 500
but the query is very slow(about take 15s)
 
Is there some another way can do fast ?

 
  _____  

superman0920

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