On 20/07/16 17:35, Even Rouault wrote: > Hi, > >> I am a bit confused by the WFS option *"Only request features >> overlapping the view extent"*. >> >> In general, that's what every provider does by default and is a safe >> strategy to use. If this option is unchecked, QGIS will just start >> downloading features randomly until it hits a server limit (or not). > Time to upgrade the servers to support WFS 2.0 paging :-) Who could object to that :-) > >> The only reason why one would possibly want to do that is to warm a >> cache on a layer where he know he will be getting all the features (in a >> reasonable time). In this case, the option should probably be renamed >> (to something containing the word "cache"). > The provider always cache (meaning keep in a temporary database the features > retrieved), whatever you check or uncheck this option. For example with the > default behaviour, zoom in in some region and wait for some or all features > to > be retrieved, and zoom out. The provider will use the already downloaded > features first and then return the features coming from the background > downloading of the new request (using gml:id/fid to make sure not to return > already cached features). In which case does that help? Isn't every cached feature downloaded again (with potentially more up to date information) anyway? > >> Question: *is **there anybody using WFS with this option unchecked?* And >> if yes, for what reason? > Yes it is needed for some use cases. There are servers that have buggy > behaviour with BBOX requests combined with other filters. Or the cost of > solving a spatial request might be super high, making it more practical to > issue a GetFeature without a BBOX. Ok, so it should be a super well hidden checkbox with a big warning sign next to it?
Matthias _______________________________________________ Qgis-developer mailing list [email protected] List info: http://lists.osgeo.org/mailman/listinfo/qgis-developer Unsubscribe: http://lists.osgeo.org/mailman/listinfo/qgis-developer
