To enable the Database Smart Flash Cache, you configure the following parameters:
DB_FLASH_CACHE_FILE = ‘/dev/flash_device_1’ , ‘/dev/flash_device_2’
DB_FLASH_CACHE_SIZE=64G
What is the result when you start up the database instance?
A.
It results in an error because these parameter settings are invalid.
B.
One 64G flash cache file will be used.
C.
Two 64G flash cache files will be used.
D.
Two 32G flash cache files will be used.
Explanation:
100% A
You can specify up to 16 file sizes, for each of the flash memory devices specified with DB_FLASH_CACHE_FILE. For example, if there are three flash raw devices, you can specify the sizes of EACH device. Also tested…
Agree with smbd.smth:
SQL> startup nomount;
ORA-12427: invalid input value for db_flash_cache_file parameter
B
http://docs.oracle.com/cd/E16655_01/server.121/e17615/refrn10316.htm#REFRN10316
You give the link to the Oracle documentation which invalidates your own response…
Nowhere the doc says that you can define only one db_flash_cache_size if you have set multiple db_flash_cache_file.
A is the good answer
correct answer is A.
if “DB_FLASH_CACHE_SIZE=64G, 64G’ then B would be correct.
A is correct answer. DB_FLASH_CACHE_SIZE must be defined for both the devices to be valid.
A
A
DB_FLASH_CACHE_FILE filename for the flash memory or disk group representing a collection of flash memory.
Specifying this parameter without also specifying the DB_FLASH_CACHE_SIZE initialization parameter is not allowed.
If you specify 2 files, and for the sizes, if you give only one, it will give an error.
Answer is A.
B is correct.
let say both devices are of equal size 64G, 64G. then parameter setting should be
DB_FLASH_CACHE_SIZE=64G,64G
To disable a device, remove the entry from size for that deivce.
So setting in question will use one device only ( first one).
Hey,
SQL> show parameter flash
NAME TYPE VALUE
———————————— ———– ——————————
db_flash_cache_file string /dev/sdb, /dev/sdc
db_flash_cache_size big integer 1G, 1G
SQL> select flashfile#, name, enabled from v$flashfilestat;
FLASHFILE# NAME ENABLED
———- ——— ———-
1 /dev/sdb 1
2 /dev/sdc 1
SQL>
SQL> alter system set db_flash_cache_size=1G scope=SPFILE;
System altered.
SQL> shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup
ORA-12427: invalid input value for db_flash_cache_file parameter
SQL>
So in my tests it fails to startup with two devices but only one size specification. So A for me.