Le mercredi 17 décembre 2014 13:18:16, Even Rouault a écrit : > Le mercredi 17 décembre 2014 13:03:13, Pepijn Van Eeckhoudt a écrit : > > On 17/12/14 11:18, Even Rouault wrote: > > > In the update scenario like gdaladdo, an optimization that is used when > > > creating the file from scratch (gdal_translate) isn't applied. You can > > > try adding "--config OGR_SQLITE_SYNCHRONOUS OFF" on the gdaladdo > > > command line. I suspect this must be the issue. I was a bit hesitant > > > to apply it by default in update cases since it means that a > > > interruption of the process (ctrl-c) could damage the database. But > > > this is generally the case for other formats, so we probably could > > > apply it too. > > > > Not sure if this is feasible in GDAL, but what I did in my own code is > > to use transactions to speed things up. All the tile inserts are batched > > in transactions of 100 tiles or so. > > I had a look at the driver code, but it wasn't immediately clear to me > > if this is already happening or not. Doesn't look like it though. > > No, it doesn't for now. Could indeed be a potential optimization.
Implemented now. Greatly improves performance of overview creation indeed. > > > Pepijn > > _______________________________________________ > > gdal-dev mailing list > > [email protected] > > http://lists.osgeo.org/mailman/listinfo/gdal-dev -- Spatialys - Geospatial professional services http://www.spatialys.com _______________________________________________ gdal-dev mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/gdal-dev
