Use the ALTERTABLETRUNCATESUBPARTITION statement to remove all rows from a subpartition of a composite partitioned table. Corresponding local index subpartitions are also truncated.
The following statement shows how to truncate data in a subpartition of a table. In this example, the space occupied by the deleted rows is made available for use by other schema objects in the tablespace.
ALTER TABLE diving
TRUNCATE SUBPARTITION us_locations