public void setRecordReader(RecordReader<K, V> recordReader) {
    this.recordReader = recordReader;
  }
This class prepares an IOContext, and provides the ability to perform a binary search on the
data.  The binary search can be used by setting the value of inputFormatSorted in the
MapreduceWork to true, but it should only be used if the data is going to a FilterOperator,
which filters by comparing a value in the data with a constant, using one of the comparisons
=, &lt;, &gt;, &lt;=, &gt;=.  If the RecordReader's underlying format is an RCFile, this object can perform
a binary search to find the block to begin reading from, and stop reading once it can be
determined no other entries will match the filter.
ql/src/java/org/apache/hadoop/hive/ql/io/HiveContextAwareRecordReader.java