Hi, I took timings about adding 115 GML files (548 MB together, 3.2 million linestrings) into a Spatialite table. With default settings the table gets initialized with spatial index which makes following inserts slower. Another alternative is to create the table without spatial index, append all the data first and as a last step create spatial index for the ready made table.
With spatial index on: Append + index: 71 minutes With spatial index off: Append: 9 minutes Create spatial index: 6 minutes Total: 15 minutes I was rather happy with the initial conversion speed until I made this test which revealed that creating spatial index as a final step made the whole process more than four times faster! This way both data table and spatial index are probably in contiguous chunks in the SQLite datafile and there is no need for post process VACUUM. Vacuuming in SQLite is rather slow and for this 1.3 GB database it takes more than 4 minutes to run. Suggestion: Add a new performance hint on page http://www.gdal.org/ogr/drv_sqlite.html "If many source files will be collected into the same Spatialite table it can be much faster to initialize the table without a spatial index by using -lco SPATIAL_INDEX=NO and to create spatial index with a separate command after all the data are appended. Spatial index can be created with ogrinfo command ogrinfo db.sqlite -sql "SELECT CreateSpatialIndex('table_name','geometry_column_name')" Perhaps it could also be mentioned as a performance hint that VACUUUM can also be done from orginfo as ogrinfo db.sqlite -sql "VACUUM" -Jukka Rahkonen- _______________________________________________ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev
