I have a layer coming from a WFS that itself gets its data from a PostGIS database via GeoServer.
As of the capatbilities of the service I can perform a Crosses operation in oder to select features that cross a specific geometry. I assume such a request is directly mapped to the appropriate geometry-function within PostGIS, i.e. ST_Crosses
.
I wonder if performing a spatial query in QGIS using "Select by Location" for instance will actually route to a spatial query on the database, or if QGIS just uses its own client-side implementation. Or in other words: Does QGIS use the spatial capabilities of the underlying datastore?