private void markExplicitTransaction(QueryPlan queryPlan) throws LockException {
    isExplicitTransaction = true;
    if (++startTransactionCount > 1) {
      throw new LockException(null, ErrorMsg.OP_NOT_ALLOWED_IN_TXN, queryPlan.getOperationName(),
        JavaUtils.txnIdToString(getCurrentTxnId()), queryPlan.getQueryId());
    }
  }
Watermark to include in error msgs and logs
@param queryPlan
@return
ql/src/java/org/apache/hadoop/hive/ql/lockmgr/DbTxnManager.java