You have installed two 64G flash devices to support the Database Smart Flash Cache feature on your database server that is running on Oracle Linux.
You have set the DB_SMART_FLASH_FILE parameter:
DB_FLASH_CACHE_FILE= ‘/dev/flash_device_1 ‘,’ /dev/flash_device_2′
How should the DB_FLASH_CACHE_SIZE be configured to use both devices?
A. Set DB_FLASH_CACHE_ZISE = 64G.
B. Set DB_FLASH_CACHE_ZISE = 64G, 64G
C. Set DB_FLASH_CACHE_ZISE = 128G.
D. DB_FLASH_CACHE_SIZE is automatically configured by the instance at startup.
* Smart Flash Cache concept is not new in Oracle 12C – DB Smart Flash Cache in Oracle 11g.
In this release Oracle has made changes related to both initialization parameters used by DB Smart Flash cache. Now you can define many files|devices and its sizes for “Database Smart Flash Cache” area. In previous releases only one file|device could be defined.
DB_FLASH_CACHE_FILE = /dev/sda, /dev/sdb, /dev/sdc
DB_FLASH_CACHE_SIZE = 32G, 32G, 64G
So above settings defines 3 devices which will be in use by “DB Smart Flash Cache”
/dev/sda – size 32G
/dev/sdb – size 32G
/dev/sdc – size 64G
New view V$FLASHFILESTAT – it’s used to determine the cumulative latency and read counts of each file|device and compute the average latency