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

Examine the description of the BOOKS table:

The table has 100 rows.
Examine this sequence of statements issued in a new session:
INSERT INTO books VALUES ('ADV112', 'Adventures of Tom Sawyer', NULL, NULL); SAVEPOINT a; DELETE FROM books; ROLLBACK TO SAVEPOINT a; ROLLBACK; Which two statements are true? (Choose two.)

Which two statements are true about Enterprise Manager Database Express? (Choose two.)

You want to use table compression suitable for OLTP that will:
1. Compress rows for all DML statements on that table
2. Minimize the overheads associated with compression
Which compression option is best suited for this?

Which three statements are true about sequences in a single instance Oracle database?