[postgis-users] using && operator

[Jan Saalbach]

Hi List,
how do I check if two 3d-point sets overlap? I see the && operator  
should be able to compare the bounding boxes, but how do I do it? I  
can not get the && or ST_Intersects function to work. Here is what I  
am trying to do:

SELECT ST_Collect(pkt) FROM pktbsp && ST_Collect(pkt) FROM pktbsp2;

pkt are GeometryColumns filled with 3dpoints. pktbsp and pktbsp2 are  
the respective tables.

How can I check this?

Reagrds,
Jan