Hi, I want to report about the outcome of https://github.com/qgis/QGIS-Enhancement-Proposals/issues/172 "Use of FileGeodatabase spatial index in OpenFileGDB driver"
This work has been successfully completed into GDAL master (for upcoming GDAL 3.2) per https://github.com/OSGeo/gdal/pull/2771 , and automatically benefits to QGIS when it uses the OpenFileGDB driver. Some figures on a version from of few years ago of the dataset at https://data.linz.govt.nz/layer/50772-nz-primary-parcels/, featuring 2 484 646 polygons, 773 MB:"ogrinfo -spat 174.949909 -41.143842 175.684529 -40.594600 -al -so -noextent" (thus counting the number of features intersecting the spatial filter), which returns 81 046 polygons, nows runs in 400 ms with GDAL 3.2dev and the OpenFileGDB driver, versus 6.7 s before (full scan), vs 890 ms with the FileGDB driver (with FileGDB SDK 1.5). All figures given with debug builds, and on a hot run (so with most pages cached by the OS). Interactive display of this dataset in QGIS with the OpenFileGDB driver is as fluid as with the FileGDB one. Comparing behaviour of OpenFileGDB and FileGDB drivers with strace shows that they read a similar amount of data in the .spx file, which confirms it is uses correctly. The filegdb reverse engineered specification was also updated in https://github.com/rouault/dump_gdbtable/wiki/FGDB-Spec#specification-of-spx-files Thanks to qgis.org grant program for making this improvement possible. Best regards, Even -- Spatialys - Geospatial professional services http://www.spatialys.com
_______________________________________________ QGIS-Developer mailing list [email protected] List info: https://lists.osgeo.org/mailman/listinfo/qgis-developer Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-developer
