@Override
    public void writeIndex(StreamName name, OrcProto.RowIndex.Builder index) throws IOException {
      // TODO: right now we treat each slice as a stripe with a single RG and never bother
      //       with indexes. In phase 4, we need to add indexing and filtering.
    }
For !doesSourceHaveIncludes case, stores global column IDs to verify writer columns.
For doesSourceHaveIncludes case, stores source column IDs used to map things.
llap-server/src/java/org/apache/hadoop/hive/llap/io/encoded/SerDeEncodedDataReader.java