@Override
    public byte updateStateByte(Byte previousValue) {
      // Not used by the direct access client -- native vector map join.
      throw new UnsupportedOperationException("Updating the state by not supported");
    }
If we received data with tags from ReduceSinkOperators, no keys will match. This should
not happen, but is important enough that we want to find out and work around it if some
optimized change causes RSO to pass on tags.
ql/src/java/org/apache/hadoop/hive/ql/exec/persistence/MapJoinBytesTableContainer.java