I'm new to GIS applications and trying to figure out what options I have for visualizing spatial query results that combine raster and vector data using OpenLayers/GeoExt/GeoServer/PostGIS.
A hypothetical query that could be created on a web client by a user might be: "give me all raster pixels with an index value of 1 that are within a distance of 120 meters of any river (line vector feature) and touching or inside a selected watershed (polygon vector feature)".
It's also not super clear how I can visualize mixed raster/vector query results. I've seen some purely vector examples that create a vector map layer in OpenLayers and when the vector features come back to the client, those features are simply pushed onto the vector map layer. Assuming a mixed vector+raster query is possible in PostGIS, should I be expecting to follow the same process (get vector features back, then add them to a vector OpenLayers layer) for visualization?
Lastly, does it even sound like I'm thinking along the right lines here or am I attempting to do something that is difficult or even impossible given the feature sets available in Open Source GIS tools these days?