[postgis-users] Check geometry for true intersection using ST_Relate

Andrea Peri 2007 aperi2007 at gmail.com
Sun Jul 18 03:44:37 PDT 2010


I need to retrieve from a table all the geometry that intersect a given 
polygon .
But the standard ST_Intersection is no good for me because it return 
true even if
two geometry are only touching on their boundary without having a 
partially overlap each other.

I don't find other type of intersection that don't responde true on touch.
So I try to use the ST_Relate(..)
But I don't understand exactly how define the matrix to use.

I don't sure if the correct matrix to declare is this

String overlaps = "T********";

or this

String overlaps = "2********";

my geometry are all polygon so perhaps declaring
String overlaps = "T********";
can be sufficient ?

Many thx,

Andrea Peri.

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