@Override
        public boolean doNext(WritableComparable key, Writable value) throws IOException {
          // if current pos is larger than shrinkedLength which is calculated for
          // each split by table sampling, stop fetching any more (early exit)
          if (target.shrinkedLength > 0 &&
              context.getIoCxt().getCurrentBlockStart() > target.shrinkedLength) {
            return false;
          }
          return super.doNext(key, value);
        }
Set context for this fetch operator in to the jobconf.
This helps InputFormats make decisions based on the scope of the complete
operation.
@param conf the configuration to modify
@param paths the list of input directories
ql/src/java/org/apache/hadoop/hive/ql/exec/FetchOperator.java