public void setNextVectorBatchGroupStatus(boolean isLastGroupBatch) throws HiveException {
    // Do nothing.
  }
Process the row.

@param row
         The object representing the row.
@param tag
         The tag of the row usually means which parent this row comes from.
         Rows with the same tag should have exactly the same rowInspector
         all the time.
ql/src/java/org/apache/hadoop/hive/ql/exec/Operator.java