@Override
  public void releaseLocks(List<HiveLock> hiveLocks) throws LockException {
    // If there's no lock manager, it essentially means we didn't acquire locks in the first place,
    // thus no need to release locks
    if (lockMgr != null) {
      lockMgr.releaseLocks(hiveLocks);
    }
  }
An implementation of {@link HiveTxnManager} that does not support
transactions.  This provides default Hive behavior.
ql/src/java/org/apache/hadoop/hive/ql/lockmgr/DummyTxnManager.java