protected DatasetPrefixesTDB makePrefixTable(Location location, DatasetControl policy, StoreParams params) {
String primary = params.getPrimaryIndexPrefix() ;
String[] indexes = params.getPrefixIndexes() ;
TupleIndex prefixIndexes[] = makeTupleIndexes(location, primary, indexes, new String[]{params.getIndexPrefix()}, params) ;
if ( prefixIndexes.length != 1 )
error(log, "Wrong number of prefix table tuples indexes: " + prefixIndexes.length) ;
String pnNode2Id = params.getPrefixNode2Id() ;
String pnId2Node = params.getPrefixId2Node() ;
NodeTable prefixNodes = makeNodeTableNoCache(location, pnNode2Id, pnId2Node, params) ;
NodeTupleTable prefixTable = new NodeTupleTableConcrete(primary.length(),
prefixIndexes,
prefixNodes, policy) ;
DatasetPrefixesTDB prefixes = new DatasetPrefixesTDB(prefixTable) ;
log.debug("Prefixes: " + primary + " :: " + String.join(",", indexes)) ;
return prefixes ;
}