Oracle OCP 19c 认证1Z0-083考试(第2题)

Posted 2021-07-09 itsaka

 

While backing up to an SBT channel, you determine that the read phase of your compressed Recovery Manager (RMAN) incremental level 0 backup is a bottleneck.
FORCE LOGGING is enabled for the database.
Which two could improve read performance? (Choose two.)

• A. Increase the size of tape I/O buffers.
• B. Disable FORCE LOGGING for the database.
• C. Increase the size of the database buffer cache.
• D. Enable asynchronous disk I/O.
• E. Increase the level of RMAN multiplexing.

answer is D,E

C is incorrect. RMAN does not use database buffer cache. . Asynchronous I/O (D) and multiplexing (Parallel read - E) improve read performance.

rman doesn't use db buffer cache: RMAN Backup Performance (Doc ID 360443.1) "RMAN uses its own buffer cache separate from the database buffer cache"