public GenericUDAFResolver getGenericUDAFResolver(String functionName) throws SemanticException {
    FunctionInfo info = getFunctionInfo(functionName);
    if (info != null) {
      return info.getGenericUDAFResolver();
    }
    return null;
  }
Unregisters all the functions belonging to the specified database
@param dbName database name
@throws HiveException
ql/src/java/org/apache/hadoop/hive/ql/exec/Registry.java