Hi On Thu, Feb 27, 2014 at 4:47 PM, kimaidou <[email protected]> wrote: > Hi list, > > I have some concerns about spatial indexes in QGIS. Spatial indexes are very > usefull, and for me rather mandatory as soon as you deal with more than 100 > features. > > > I would like to share some ideas about them : > > 1) Extend QGIS so that it can create spatial indexes for more vector format. > If I am correct, for now only Shapefiles and Database vector layers can have > a spatial index created by QGIS . Why not for GeoJson, CSV files, etc ?
The create spatial index functionality is handled by data provider - in this case GDAL/OGR - at some point it was available only for shapefiles, not sure if anything changed since then. > 2) If possible, create a spatial index for each vector layer added to the > canvas if no one is already present. Since it is a quite fast operation, the > small time needed is worth it. I am not sure this is the right thing to do it automatically. It could however suggest it for large layers for better performance. > 3) If possible, update the spatial index (replace the old qix by a new one) > every time the vector layer is updated. No need to do so for database > layers, but this can be very usefull for big shapefiles. I have seen some > people creating a spatial index, then as time passes, they add more and more > data into the shapefile but forget to update the spatial index. Sometimes > this can lead to some data not displayed in QGIS because QGIs seems to rely > on the outdatedSpatial index. Doesn't OGR handle the update of the spatial index automatically? Regards Martin _______________________________________________ Qgis-developer mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/qgis-developer
