For indexes that are changing rapidly in NRT situations, fcs (stands for

Field Cache per Segment) may be a better choice than the default fc.
(saves memory)
see: http://wiki.apache.org/solr/SimpleFacetParameters#facet.method

source/net/yacy/cora/federate/solr/connector/AbstractSolrConnector.java

@@ -308,6 +308,7 @@ public abstract class AbstractSolrConnector implements SolrConnector {
         params.setFacet(true);
         params.setFacetLimit(maxresults);
         params.setFacetSort(FacetParams.FACET_SORT_COUNT);
+        params.setParam(FacetParams.FACET_METHOD, FacetParams.FACET_METHOD_fcs);
         params.setFields(fields);
         params.clearSorts();
         params.setIncludeScore(false);

source/net/yacy/search/query/QueryParams.java

@@ -520,6 +520,7 @@ public final class QueryParams {
             params.setFacet(true);
             params.setFacetLimit(this.maxfacets);
             params.setFacetSort(FacetParams.FACET_SORT_COUNT);
+            params.setParam(FacetParams.FACET_METHOD, FacetParams.FACET_METHOD_fcs);
             for (String field: this.facetfields) params.addFacetField(field);
         } else {
             params.setFacet(false);