[GRASS-user] RE: Problem querying layers other than '1' in gi s.m

[Moritz Lennert]

Radim Blazek wrote:
> On 9/22/06, Moritz Lennert <mlennert at club.worldonline.be> wrote:
>> > There are more, examples:
>> > - Overlapping areas, e.g. a road on a bridge and a road below
>> > - Many records with different time for the same point
>>
>> Both of these examples use different layers to store information, not
>> different category values in the same layer, or ?
> 
> No. One layer, more cats per geometry.

What's the advantage of doing this in one layer ? Why not use one layer 
with one category value and store different time records for the same 
category in the one table linked to that layer ?

Moritz