Using GeoServer, I need to provide a graphical representation of the distribution of some metrics on a geographical basis. The geographical regions will be coloured and labelled according to the value of that metric.
I would like to have a "world" layer (containing all the continents and only continents), a "Europe" layer (containing only countries from Europe) and a "France" layer (containing all the cities in France). So to speak, "a tree of layers containing the immediate children", given that these entities (continents/countries/cities) reside in three distinct tables with one-to-many relationships defined.
I haven't found any "filtering" option when defining a layer from a PostGIS store, so a "cities" layer can only be based on the whole cities table (not on the cities in country X). Is there something I missed ?
P.S. I would rather have distinct layers than having one big layer and filtering with every request, because I think the caching feature can only refer to layers. Is this assumption correct ?