private ExprNodeConstantDesc createConstDesc(
      String skewedValue, ExprNodeColumnDesc keyCol) {
      ObjectInspector inputOI = TypeInfoUtils.getStandardJavaObjectInspectorFromTypeInfo(
        TypeInfoFactory.stringTypeInfo);
      ObjectInspector outputOI = TypeInfoUtils.getStandardJavaObjectInspectorFromTypeInfo(
        keyCol.getTypeInfo());
      Converter converter = ObjectInspectorConverters.getConverter(inputOI, outputOI);
      Object skewedValueObject = converter.convert(skewedValue);
      return new ExprNodeConstantDesc(keyCol.getTypeInfo(), skewedValueObject);
    }
Converts the skewedValue available as a string in the metadata to the appropriate object
by using the type of the column from the join key.
@param skewedValue
@param keyCol
@return an expression node descriptor of the appropriate constant
ql/src/java/org/apache/hadoop/hive/ql/optimizer/SkewJoinOptimizer.java