@Override
  public VectorSMBJoinDesc clone() {
    VectorSMBJoinDesc clone = new VectorSMBJoinDesc();
    return clone;
  }
VectorSMBMapJoinDesc.

Extra parameters beyond SMBMapJoinDesc just for the VectorSMBMapJoinOperator.

We don't extend SMBMapJoinDesc because the base OperatorDesc doesn't support
clone and adding it is a lot work for little gain.
ql/src/java/org/apache/hadoop/hive/ql/plan/VectorSMBJoinDesc.java