The Storage Specification

By default, all of the partition extents that had been allocated to the 4specified table and to its indexes are released after TRUNCATE successfully 4executes, but you can include the DROP STORAGE keywords to achieve the same 4result, making the storage space available for other database objects. The 4first extent size remains the same as it was before the TRUNCATE operation 4released the storage.

Alternatively, if it is your intention to keep the same storage space allocated 4to the same table for subsequently loaded data, specify the REUSE STORAGE 4keywords to prevent the space from being deallocated. The REUSE STORAGE option 4of TRUNCATE can make storage management more efficient in applications where 4the same table is periodically emptied and reloaded with new rows.

Whether you specify DROP STORAGE or REUSE STORAGE, any out-of-row 4data values are released for all rows of the table when the TRUNCATE transaction 4is committed. Storage occupied by any BLOB or CLOB values that become unreferenced 4in the TRUNCATE transaction is also released.