Comment 1 for bug 929561

An area filter can be done in a number of ways, it can be done with GeoDjango/PostGIS, it can also be done with the CQL (common query language) which is integrated into the GXP/OpenLayers libraries.
The question becomes what is the exact requirement, and which option will be most efficient.
I found a user posting the later question to the OpenLayers mailing list and should be considered: http://lists.osgeo.org/pipermail/openlayers-users//2011-August/021812.html
In short: "Spatial filtering in GeoServer is as efficient as in PostGIS"