[postgis-users] Overlaps query

[Thorsten Kraus]

Hi,

I want to query a geometry column using the PostGIS function 'overlaps'. The
query shoult return the number of overlapping geometries in a table.
Here is the query I tried:

SELECT COUNT(a.id) FROM tbl1 a, tbl1 b WHERE OVERLAPS(a.geom, b.geom) AND
a.id <> b.id

When I run the query, it takes a long time (96528ms) until PostGIS returns
the result although my table only contains 10 rows. Is there a possibility
to increase the performance of this query?

Regards,
Thorsten
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