Which two statements are true about setting the FAST_START_MTTR_TARGET initialization
parameter to a nonzero value? (Choose two.)
A.
The MTTR advisor will be disabled
B.
Automatic checkpoint tuning will be enabled
C.
The value for the LOG_CHECKPOINT_INTERVAL initialization parameter will be override the value
for FAST_START_MTTR_TARGET
D.
The time taken to recover the instance after the crash is always exactly the same as the value
given for the FAST_START_MTTR_TARGET initialization parameter
Setting the database parameter FAST_START_MTTR_TARGET to a value greater than zero enables the fast-start checkpointing feature — automated Checkpoint Tuning of MTTR
MTTR advisory is disabled because either FAST_START_IO_TARGET or LOG_CHECKPOINT_INTERVAL is set.
FAST_START_MTTR_TARGET
To enable MTTR advisory, set the initialization parameter FAST_START_MTTR_TARGET to a nonzero value. If FAST_START_MTTR_TARGET is not specified, then MTTR advisory will be OFF.
When MTTR advisory is ON, it simulates checkpoint queue behavior under five different MTTR settings
To enable MTTR Advisor, set the two initialization parameters STATISTICS_LEVEL and FAST_START_MTTR_TARGET.
STATISTICS_LEVEL governs whether all advisors are enabled and is not specific to MTTR Advisor. Ensure that it is set to TYPICAL or ALL. Then, whenFAST_START_MTTR_TARGET is set to a nonzero value, the MTTR Advisor is enabled.
A so wrong.
MTTR guidance can be converted into a multiple parameter values FAST_START_MTTR_TARGET so within the time required (or as close as possible within this time range) to enable instance recovery.
Please note, disabled
FAST_START_MTTR_TARGET parameters explicitly set to 0 disables MTTR advisor.
Therefore, D error. Is a point in time within the time required or as close as possible within the scope of this event is not specified.
FAST_START_MTTR_TARGET parameter setting system must support service level agreements. If the value of MTTR target smaller, because it will increase the number of writes to the data files to increase I / O overhead (which can affect performance). However, if the MTTR target set too high, the instance after a crash takes longer to recover.
The quick start to the checkpoint feature is enabled by specifying the value of the desired non-zero average time (MTTR), this value will be used to set FAST_START_MTTR_TARGET initialization parameters. This parameter controls the amount of time the database crash recovery takes a single instance. When you enable Quick Start Checkpoint feature, oracle will automatically maintain the speed checkpoint, they had reached the MTTR of the request. If the value is set to 0, will disable this feature.
Therefore, B is correct.