[GRASSLIST:4217] Generating new linked attribute table after v.overlay

[Craig Aumann]

I'm working in 5.7.

Suppose we have two polygons which have attributes linked to an
associated PostGRESQL database.  

i.e. 

----------------
|   1   |  2    |
|       |       |
|       |       |
|       |       |
-----------------

linking off to a table:

LINK_KEY   STATE
1           57
2           59


I now overlay  another polygon:
----------------
|   10  |  11   |
|       |       |
*******************
|   12  |  13   |
******************
|   14  |  15   |
-----------------

and what I want to do is end up with an associated table linked to the
result of the overlay that looks like this:

LINK_KEY  STATE NEW_STATE
10          57       57
11          59       59
12          57      157
13          59      159
14          57       57 
15          59       59

I need a few kicks in the right direction (alright, I need to have my
hand held in a major way!) to figure out how to proceed following
v.overlay to  ensure that each new polygon resulting from the overlay
has one (and only one!) unique link_key into the new attribute table AND
also how to do the associated query processing based on the STATE (and
other columns) of the original polygons (stored in their original linked
table above) which the overlaid polygon intersects.  


Thanks!
Craig