public void unregisterFunctions(String dbName) throws HiveException {
    lock.lock();
    try {
      Set<String> funcNames = getFunctionNames(dbName.toLowerCase() + "\\..*");
      for (String funcName : funcNames) {
        unregisterFunction(funcName);
      }
    } finally {
      lock.unlock();
    }
  }
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