I'm having some doubts concerning the layer mechanism.
Creating a new layer (ie a new connection between a vector and a DB table), I've imported a vector (rivers) through v.in.ogr, then I've cloned the original table:
db.copy from_table=rivers to_table=rivers_clone
I've created a new connection:
v.db.connect map=rivers table=rivers_clone layer=2
At this point I supposed that the last command had created all the needed structures and fields for the new layer (2), but if I print the categories:
v.category input=rivers layer=2 option=print
no categories are displayed (while they are listed if I choose layer 1).
Question: I thought that a new connection used the same vector categories, but it seems I was wrong. How to make the layer 2 use the same vector categories from layer 1?