[postgis-users] Out of memory error with BOX3D

[Jan Saalbach]

Hi all,
an "out of memory error" occurs when I issue the following command:

SELECT BOX3D(ST_COLLECT(punkte)) FROM rohdaten WHERE id=109;

"punkte" is a GeometryColumn filled with POINT3D, 17 million for id=109. 
The machine has 4GB of ram.

I chose the box3d over the ConvexHull function because I thought it 
would be much faster, and much less memory consuming. Apparently I was 
wrong about memory consuming.

What I do not get is why a computation as simple as "min x,y,z and max 
x,y,z all at once" should consume that much memory. Can someone explain 
to me what point I am missing?

Issuing MIN(ST_X... MIN(ST_Y... commands one after another works fine 
and is quite fast.

Regards,
Jan