public void setSkewedValueLocationMap(List<String> valList, String dirName) {
    Map<List<String>, String> mappings = tTable.getSd().getSkewedInfo()
        .getSkewedColValueLocationMaps();
    if (null == mappings) {
      mappings = new HashMap<List<String>, String>();
      tTable.getSd().getSkewedInfo().setSkewedColValueLocationMaps(mappings);
    }

    // Add or update new mapping
    mappings.put(valList, dirName);
  }
Marker SemanticException, so that processing that allows for table validation failures
and appropriately handles them can recover from these types of SemanticExceptions
ql/src/java/org/apache/hadoop/hive/ql/metadata/Table.java