private ListSinkOperator completed(ParseContext pctx, FetchWork work) {
      for (ReadEntity input : inputs) {
        PlanUtils.addInput(pctx.getSemanticInputs(), input);
      }
      return replaceFSwithLS(fileSink, work.getSerializationNullFormat());
    }
Tries to convert simple fetch query to single fetch task, which fetches rows directly
from location of table/partition.
ql/src/java/org/apache/hadoop/hive/ql/optimizer/SimpleFetchOptimizer.java