@Override
  public long getStart() {
    if (inputSplits != null && inputSplits.length > 0
        && inputSplits[0] instanceof FileSplit) {
      return ((FileSplit) inputSplits[0]).getStart();
    }
    return 0;
  }
The position of the first byte in the file to process.
ql/src/java/org/apache/hadoop/hive/ql/io/BucketizedHiveInputSplit.java