private void lockAllBuffers(StripeData sd) {
    for (int i = 0; i < sd.getData().length; ++i) {
      LlapSerDeDataBuffer[][] colData = sd.getData()[i];
      if (colData == null) continue;
      for (int j = 0; j < colData.length; ++j) {
        LlapSerDeDataBuffer[] streamData = colData[j];
        if (streamData == null) continue;
        for (int k = 0; k < streamData.length; ++k) {
          boolean canLock = bufferManager.incRefBuffer(streamData[k]);
          assert canLock;
        }
      }
    }
  }
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