"inspired" by HIVE-5286.
Partition column for dates should be stored as either integer, or as fixed representation e.g. yyyy-mm-dd. External representation can remain varied as is.
add date support to metastore JDO/SQL
Recent change to schema upgrade scripts breaks file naming conventions
schemaTool failure when date partition has non-date value
Revert HIVE-5700 - enforce single date format for partition column storage