[GRASS-dev] large vector problems

[Moritz Lennert]

On 26/02/09 08:56, Vincent Bain wrote:
> Hello,
> reading this thread, and being sometimes concerned with large vector
> files (associated with big related tables), I wonder if it's worth
> manually creating indexes (on cat field) : can it be a effective way to
> speed up queries, or is the kink elsewhere, at the geometric level (data
> handled by grass, not the linked DBMS) ?


AFAIK, an index on the cat field is created automatically when a new 
vector is created, but if you link an existing table to a vector map, no 
indices are created. So, yes, creating an index on your cat field can 
make a significant difference for operations involving that field...

Moritz