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Database Smart Flash Cache in Oracle

Database Smart Flash Cache in Oracle

Database Smart Flash Cache is the new feature in Oracle 12c. It will help to increase the database buffer cache size using Solid State Device. It will greatly improve the performance of Oracle database by reducing disk I/O.

Note:
1. It only supported on Oracle Linux or Solaries Operating System.
2. Database smart flash cache is configured as 2 time to 10 times of Database buffer cache size or SGA size

Configure the Database Smart Flash Cache

-- Set the parameter in the SPFILE
Alter system set db_flash_Cache_File = /dev/sda scope=spfile;
Alter system set db_flash_cache_size = 32G scope=spfile;

-- Restart the database
shutdown immediate
startup

Configure to Setup multiple paths parameters

DB_FLASH_CACHE_FILE = /dev/sda, /dev/sdb, /dev/sdc
DB_FLASH_CACHE_SIZE = 32G, 32G, 64G

Flush the Database Smart flash cache

ALTER SYSTEM FLUSH FLASH_CACHE;

For disable it you can size it to zero
Note: it is not a dynamic parameter

Alter system set db_flash_Cache_File = /dev/sda scope=spfile;
Alter system set db_flash_cache_size = 0G scope=spfile;

Shutdown immediate
Startup

Check the Usage of Database Smart Flash Cache

Select * from V$FLASHFILESTAT

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