[GRASS-user] Estimating import time for large data file

[Moritz Lennert]

On 29/05/20 14:37, Rich Shepard wrote:
> On Fri, 29 May 2020, Moritz Lennert wrote:
> 
>> Importing such a large file can take a lot of time because of the 
>> cleaning in order to get it into GRASS GIS' topological format.
> 
> Moritz,
> 
> I assumed it would taka a while, but it seemed to be stuck. Perhaps because
> that polygon was large, complex, and needed a lot of cleaning.
> 
>> I think it really depends on the specific file in terms of geometry
>> complexity and cleanliness, so difficult to pre-determine. I regularly
>> launch large import jobs overnight.
> 
> Then that's what I'll do tonight: I'll start it running in screen before I
> log off and let it do it's thing for as long as it wants.
> 
>> You should see an information about its progress in the different 
>> cleaning
>> steps (note that some cleaning is repeated).
> 
> I was using the GUI because I needed to create a new location and have
> forgotten how to create a new location and mapset from the command line.


grass --help is your friend ;-)

	grass -c epsg:4326 GISDBASE/LOCATION

replace GISDBASE and LOCATION with the respective names

-c can also be used with a file:

-c /path/to/georeferenced/file

Another, untested, path for possibly speeding up import: use ogr2ogr 
with the -simplify option to first simplify the geometry, if that is 
possible in your case. Would be interesting to benchmark v.in.ogr alone 
against ogr2ogr -simply + v.in.ogr.

Moritz