Partitioned index-organized tables are very useful for providing improved performance, manageability, and availability for index-organized tables.
For partitioning an index-organized table:
Partition columns must be a subset of the primary key columns.
Secondary indexes can be partitioned (both locally and globally).
OVERFLOW
data segments are always equipartitioned with the table partitions.
See Also:
Oracle Database Concepts for more information about index-organized tables