Which two statements are true about space-saving features in an Oracle Database? (Choose two.)

A. Private Temporary Tables (PTTS) store metadata in memory only

B. An index that is altered to be UNUSABLE will retain its segment

C. A table that is truncated will always have its segment removed

D. If they exist for a session, Private Temporary Tables (PTTs) are always dropped at the next COMMIT OR ROLLBACK statement

E. An index created with the UNUSABLE attribute has no segment