[gdal-dev] Ogr2ogr and default value of -gt

[Even Rouault]

Le lundi 17 février 2014 16:31:55, Jukka Rahkonen a écrit :
> Jukka Rahkonen <jukka.rahkonen <at> mmmtike.fi> writes:
> > Hi,
> > 
> > The default value of -gt parameter of ogr2ogr utility is 200 which is all
> > too low for databases. Especially bad it seems to be for
> > SQLite/Spatialite and thus also for GeoPackage.
> > 
> > Are there some drivers which would suffer badly if the default value for
> > -gt would be increased to something like 2000 or 4000? It is easy to set
> > the value from the command line but most ogr2ogr usage examples we have
> > in the documentation are without -gt parameter and I am sure than very
> > many people just copy-paste the examples and run ogr2ogr unnecessarily
> > slow.
> 
> I took some timings:
> 
> ogr2ogr -f GPKG germany.gpkg germany.osm.pbf -gt 20000 -progress
> --config OSM_COMPRESS_NODES YES
> Timing: 18 minutes
> 
> ogr2ogr -f GPKG germany_2.gpkg germany.osm.pbf -progress
> --config OSM_COMPRESS_NODES YES
> Timing: 2 hours and 11 minutes

Jukka,

could you create a ticket about that ? I think we can try 20000. That thread 
http://stackoverflow.com/questions/709708/maximum-transaction-size-in-
postgresql seems to suggest that there's no problem with big transactions for 
PostgreSQL. Not sure about other backends : mysql, oci, etc... ? If anyone has 
an objection to raise against 20000 instead of 200, please speak up.

Even

> 
> -Jukka-
> 
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