private void initPartitionValues(FileSplit fileSplit, JobConf conf) throws IOException {
     int partitionColumnCount = rbCtx.getPartitionColumnCount();
     if (partitionColumnCount > 0) {
       partitionValues = new Object[partitionColumnCount];
       VectorizedRowBatchCtx.getPartitionValues(rbCtx, conf, fileSplit, partitionValues);
     } else {
       partitionValues = null;
     }
  }
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