How to filter big datasets in Geoserver WMS?

Question

Is there a good way to filter datasets with approx 50,000 features in Geoserver? I'd have to select between 100 and 200 features based on ids. These ids are different from the FeatureIds. Couldn't find a "IN" operator similar to SQL in OGC Filter Encoding Standard. Combining multiple PropertyIsEqualTo operators performs really poorly.

Answer 1

Ah. In that case, you could use GeoServer's WMS CQL filter support, i.e.:

http://<hostname>/wms?service=WMS&version=1.1.1&request=GetMap&....&cql_filter=IN ('id_1','id_2','id_3')

More information is available at http://geoserver.org/display/GEOSDOC/WMS+vendor+parameters

Answer 2

You could pass a list of feature id's in the following manner:

GET:

http://<hostname>/wfs?service=WFS&version=1.1.0&request=GetFeature&typename=foo&featureid=id_1,id_2,id_3

POST:

<?xml version="1.0" encoding="UTF-8"?>
<wfs:GetFeature version="1.1.0" outputFormat="text/xml; subtype=gml/3.1.1" service="WFS" resultType="results" xsi:schemaLocation="http://www.opengis.net/wfs http://schemas.opengis.net/wfs/1.1.0/wfs.xsd" xmlns:ogc="http://www.opengis.net/ogc" xmlns:wfs="http://www.opengis.net/wfs" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
    <wfs:Query typeName="foo">
        <wfs:PropertyName>String</wfs:PropertyName>
        <ogc:Filter>
            <ogc:FeatureId fid="id_1"/>
            <ogc:FeatureId fid="id_2"/>
            <ogc:FeatureId fid="id_3"/>
        </ogc:Filter>
    </wfs:Query>
</wfs:GetFeature>

The POST option is obviously more verbose, but less than looping PropertyIsEqualTo constructs.