@Override
  public boolean next(
    NullWritable nullWritable,
    VectorizedRowBatch vectorizedRowBatch) throws IOException {
    boolean hasMore = nextBatch(vectorizedRowBatch);
    if (bucketIdentifier != null) {
      rbCtx.setBucketAndWriteIdOf(vectorizedRowBatch, bucketIdentifier);
    }
    return hasMore;
  }
The total number of rows this RecordReader will eventually read. The sum of the
rows of all the row groups.
ql/src/java/org/apache/hadoop/hive/ql/io/parquet/vector/VectorizedParquetRecordReader.java