The partitioning engine does not support the table-level DATA/INDEX
DIRECTORY specification.

If one create a non-partitioned table with the DATA/INDEX DIRECTORY
option and then performs ALTER TABLE ... PARTITION BY on it, the
DATA/INDEX DIRECTORY specification of the old schema is ignored.

The behavior might be a bit surprising for users because the value
of a usual table option applies to all the partitions. Thus, we raise
a warning on such ALTER TABLE ... PARTITION BY.