Performing Oracle User-Managed Backups - OCP: Oracle Database 12c Administrator Certified Professional - page 22

Fast-Start Fault Recovery manages the recovery time by managing the data latency between
the persistent storage (disk) and the database cache in memory. You control Fast-Start Fault
Recovery through the use of the FAST_START_MTTR_RECOVERY parameter.
The FAST_START_MTTR_RECOVERY parameter indicates the maximum number of seconds that
any instance recovery should take. The DBW process will then manage database writes in
such a way as to attempt to meet the number of seconds that FAST_START_MTTR_RECOVERY is
set to.
Some parameters can disable Fast-Start Fault Recovery. These include the parameters
FAST_START_IO_TARGET , LOG_CHECKPOINT_INTERVAL , and LOG_CHECKPOINT_TIMEOUT . If
your database is using these parameters, then you are not taking advantage of Fast-Start
Fault Recovery.
Monitoring Instance Recovery Because instance recovery is the instance-recovery process
that is the most time sensitive, you will want to monitor your critical databases to make
sure that they can meet your instance recovery time SLAs. The view V$INSTANCE_RECOVERY
provides information on both the target mean time to recover the database and the currently
estimated mean time to recover the database. The ESTIMATED_MTTR column represents the
mean time to recover (MTTR) for the current system based on its current activity.
The Mean Time To Recover Advisor Trying to correctly set the FAST_START_MTTR_RECOVERY
parameter can be difficult. If you are sensitive to performance but also are sensitive to instance
recovery time, the Mean Time to Recover Advisor (MTTR Advisor) can be of assistance. If
you look at the V$INSTANCE_RECOVERY view, you will see the column TARGET_MTTR . This col-
umn represents the maximum attainable MTTR for that database and is calculated by the
MTTR Advisor. Both the ESTIMATED_MTTR and TARGET_MTTR columns will vary based on data-
base activity.
You can view the results of the MTTR Advisor through the V$MTTR_TARGET_ADVICE view.
This view provides an analysis of the current setting of the FAST_START_MTTR_RECOVERY
parameter and how adjustments of that parameter will impact instance recovery time.
Sybex's OCA preparation guide for Oracle Database 12 c , OCA: Oracle Data-
base 12 c Administrator Certified Associate Study Guide: Exams 1Z0-061 and
1Z0 - 062 (Sybex, 2014) by Biju Thomas, provides complete coverage on start-
ing the Oracle Database and the different stages of opening the Oracle Data-
base, so this is just a quick review.
Starting and Stopping the Database
During backup and recovery operations, you will need to know how to start up and shut
down your database correctly. To start up the database in any of the modes described in
the previous section, you will use the STARTUP command or the ALTER DATABASE command,
as required. To stop the database, you will use the SHUTDOWN command. Typically, database
startup operations are performed from SQL*Plus or Oracle Enterprise Manager.