[postgis-devel] [postgis-users] Oddity in _ST_Expand(geography) ?

[Regina Obe]

> 
> I start to think that perhaps the existing behavior is broken, and geography
> expand should rewrite the object so that it becomes something that has the
> 3-space bounds we want. Maybe an appropriately chosen multipoint, for
> example. It will be very confusing to people, though, since they tend to think
> rectangularly about bounds, even when working with spherical coordinates,
> which are very decidedly not rectangular.
> 
> Interested in thoughts,
> 
> P
> 

A  polyhedral surface.  When you cast box3d to geometry now it gives you a polyhedral surface.

SELECT ST_AsText('BOX3D(1 2 3,5 6 5)'::box3d::geometry)

POLYHEDRALSURFACE Z (((1 2 3,1 6 3,5 6 3,5 2 3,1 2 3)),((1 2 5,5 2 5,5 6 5,1 6 5,1 2 5)),((1 2 3,1 2 5,1 6 5,1 6 3,1 2 3)),((5 2 3,5 6 3,5 6 5,5 2 5,5 2 3)),((1 2 3,5 2 3,5 2 5,1 2 5,1 2 3)),((1 6 3,1 6 5,5 6 5,5 6 3,1 6 3)))

Though I guess we don't support polyhedral surfaces in geography so perhaps that's a pipe dream.

 Regina hops away before Paul has a chance to say

"That's the stupidest idea I ever heard."