[GRASS5] OGR

[Radim Blazek]

On Monday 10 May 2004 18:02, Frank Warmerdam wrote:
> Radim,
>
> I'm not sure what is the problem with using FID+1.  Could you explain
> why this does not "work in the driver"?

In GRASS, geometry and attributes are linked via "category", if I use 
category=FID+1 for geometry, it is impossible to select feature attributes
by SQL query "select * from xxx where FID=<category>".

I have enabled category = 0, so now it works.

> I'm not sure why the performance was so bad with shapefiles.  Generally,
> random access to shapefiles via FID should be relatively fast.  It would
> be interesting to see what is making this slow.

Sorry, it was my bug in GRASS, features are cached, but I forgot to change 
ID of cached feature, so the feature was read for each feature part.
Now, the time for Shapefile is almost the same as for native format.
real    0m4.453s  Shapefile via OGR
real    0m3.714s  GRASS native


Radim