@Explain(vectorization = Vectorization.SUMMARY, displayName = "inputFormatFeatureSupport", explainLevels = { Level.DEFAULT, Level.EXTENDED })
    public String getInputFormatSupport() {
      Set<Support> inputFormatSupportSet = mapWork.getInputFormatSupportSet();
      if (inputFormatSupportSet == null) {
        return null;
      }
      return inputFormatSupportSet.toString();
    }
For each map side operator - stores the alias the operator is working on
behalf of in the operator runtime state. This is used by reduce sink
operator - but could be useful for debugging as well.
ql/src/java/org/apache/hadoop/hive/ql/plan/MapWork.java