[GRASS-user] v.select incredibly slow

[Uwe Fischer]

Hi Markus,

I wrote that I used the -c flag, but in fact it was the -s flag (my error, sorry), please see here the complete command and message:

v.out.ogr -s --overwrite input=gmarest at lwk_work type=line output=d:/testout.dgn format=DGN dsco=seed=d:/a-scratch/seed/lwk_seed.dgn
ERROR 6: CreateField() not supported by this layer.
ERROR: Unable to create column <level>

important to see: the error message says that it cannot create the "level" column, which is an inherent part of the DGN format. It is NOT a user defined field. AND: that column could be written without problems in 7.0.3.
As far as I can see, there are changes in GDAL/OGR DGN driver in the way that they can also handle DGN V8 now. Maybe it has to do with those changes. But how can I figure that out? Maybe I can ask the friend named Frank Warmerdam who seems to be involved?


Mit freundlichen Grüßen,
UWE FISCHER


-----Ursprüngliche Nachricht-----
Von: Markus Neteler [mailto:neteler at osgeo.org] 
Gesendet: Sonntag, 11. April 2021 08:25
An: Uwe Fischer <gisfisch at t-online.de>
Cc: GRASS user list <grass-user at lists.osgeo.org>
Betreff: Re: [GRASS-user] v.select incredibly slow

Hello Uwe,

On Wed, Apr 7, 2021 at 7:33 PM Uwe Fischer <gisfisch at t-online.de> wrote:
>
> Hello list, hello Markus,
>
> it looks like I have the first issue with my update trials from GRASS 
> 7.0.3 to 7.8.5. The following snippet worked fine in 7.0.3
> (goal: to write out MicroStation CAD DGN-files from GRASS using a seedfile, which is just a template):
>
> v.out.ogr input=gmarest at lwk_work type=line output=d:/testout.dgn 
> format=DGN dsco=seed=d:/a-scratch/seed/lwk_seed.dgn
>
> But in 7.8.5, I get:
>
> ERROR 6: CreateField() not supported by this layer.
> ERROR: Unable to create column <level>

The "ERROR 6" indicates that it is a GDAL/OGR error, not a GRASS GIS error (for the export we make use of GDAL, hence "outsource" the creation of the desired format).

I found this in the internet:
 https://lists.osgeo.org/pipermail/gdal-dev/2006-February/008089.html
which is exactly the same error message:

Frank Warmerdam, Feb 28 15:12:15 EST 2006:
> The CreateField() messages are expected with DGN output.  The DGN 
> format has a fixed schema and doesn't support user defined fields.

> I also set the –c flag to prevent GRASS from creating the CAT column 
> since DGN only allows for certain columns, eg. LEVEL. But those cols were created without problems in the old version, so that cannot be the problem.

Note that, to prevent GRASS from creating the CAT column -c should be -s:

https://grass.osgeo.org/grass78/manuals/v.out.ogr.html
-s Skip export of GRASS category ID ('cat') attribute

HTH,
Markus