Javadoc
Calculate skewed value subdirectory directory which is used in
FileSinkOperator.java createKeyForStatsPublisher()
For example, create table test skewed by (key, value) on (('484','val_484')
stored as DIRECTORIES;
after the method, skewedValuesDirNames will contain 2 elements:
key=484/value=val_484
HIVE_LIST_BUCKETING_DEFAULT_DIR_NAME/HIVE_LIST_BUCKETING_DEFAULT_DIR_NAME