On Fri, 29 Apr 2011 09:33:42 +0200, Stefan Keller wrote > SQLite claims to be a mostly SQL compliant database and offers views. > So if views are there and work ... why should'nt this work in QGIS? >
Hi Stefan, quick answer, but exhaustive (so I hope): a) yes, that's true: SQLite fully supports VIEWs with no odd limitations b) anyway, SQLite support for Spatial Index (R*Tree) is completely different from anything else: on SQLite the Spatial Index is a separate table, and you are required to explicitly perform a sub-query in order to take profit from a Spatial Index when it's available (please note: the QGIS own data provider silently handles all this in a completely painless way) c) accordingly to all this, SpatiaLite defines any Spatial VIEW on VIEWS_GEOMETRY_COLUMNS (not on GEOMETRY_COLUMNS): and this allows to fully support Spatial Index for VIEWs as well bye Sandro _______________________________________________ Qgis-developer mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/qgis-developer
