Oracle Database 12c: Installation and Administration — Question 15

In which situations does the Database Writer process (DBWn) write to data files? (choose two).

Answer options

• A. when the RMAN recovery process starts
• B. when a user process commits a transaction
• C. when a tablespace is made read-only or taken offline
• D. when PMON cleans up dirty buffers in the database buffer cache
• E. when clean buffers for reading new blocks into the database buffer cache are not found easily

Correct answer: B, D

Explanation

The correct answers are B and D. DBWn writes to data files when a user process commits a transaction (B), ensuring that changes are saved, and when PMON cleans up dirty buffers (D), which may trigger a write to free up space. Options A, C, and E do not directly initiate a write to data files by DBWn.