Oracle Database 11g: Administration I — Question 30

Which two events always cause the LGWR to write? (Choose two.)

Answer options

• A. when a checkpoint occurs
• B. when DBWn writes dirty buffers
• C. when LGWR is notified by a server process that performs a COMMIT OR ROLLBACK
• D. when a log switch occurs
• E. when PMON restarts a server process

Correct answer: A, D

Explanation

The correct answers are A and D because a checkpoint forces LGWR to write to the redo logs, ensuring that all changes are recorded. Similarly, a log switch requires LGWR to write the current log to disk before switching to a new log file. Options B, C, and E do not necessarily trigger a write by LGWR under all circumstances.