public PrimitiveTypeInfo getPrimitiveTypeInfo() {
      switch (this) {
      case NONE:
        return TypeInfoFactory.voidTypeInfo;
      case BOOLEAN:
        return TypeInfoFactory.booleanTypeInfo;
      case BYTE:
        return TypeInfoFactory.byteTypeInfo;
      case SHORT:
        return TypeInfoFactory.shortTypeInfo;
      case DATE:
        return TypeInfoFactory.dateTypeInfo;
      case INT:
        return TypeInfoFactory.intTypeInfo;
      case LONG:
        return TypeInfoFactory.longTypeInfo;
      case STRING:
        return TypeInfoFactory.stringTypeInfo;
      case MULTI_KEY:
      default:
        return null;
      }
    }
VectorGroupByDesc.

Extra parameters beyond MapJoinDesc just for the vector map join operators.

We don't extend MapJoinDesc 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/VectorMapJoinDesc.java