Hi,
 
I went to www.opengis.org and downloaded the specification for opengis database. It seems that postgresql answers most of the specs. However it seems that some specs are limitatives in the term of projections/datums and dimensions... GIS still deal in a 2D environment instead of a 3D...
 
It gives some good indication on what are the various object types that are required and how to store them. It is good documentation to specify the catalogs and object types.... There is also a part on CORBA, but I don't know anything about CORBA...
 
Anyhow stuff to read...
 
Cheers...