Answers to Review Questions - OCP: Oracle Database 12c Administrator Certified Professional - page 663

9. A, D. Any action that causes the database to shut down abnormally will cause instance
recovery to occur when the database is restarted. Thus, a power failure of the database
server or use of the SHUTDOWN ABORT command will force instance recovery to occur.
10. E. The FAST_START_MTTR_RECOVERY parameter is used to indicate to the Oracle data-
base how much time to allow for instance recovery. Based on this parameter, the
Database Writer process will write to the database data files at a rate that will try
to match this target.
11. A, B. The DBWR and LGWR processes are critical to successful database operations
and are also critical for backup and recovery purposes. The DBW process is respon-
sible for writing changes that have occurred in the database in memory (the SGA) to
the database data files. The LGWR process is responsible for writing from the redo
log buffer to the online redo logs after a user issues a commit. The online redo log files
then become the truly persistent representation of a committed transaction.
12. C. There is always some divergence between the state of the database persistently
(reflected in the database data files) and the actual state of the database with respect to
committed transactions (which is reflected in the online redo logs when applied to the
database data files during a recovery). Instance recovery time is directly impacted by
this divergence. The more recovery that has to be applied during an instance recovery,
the longer it will take. The FAST_START_MTTR_RECOVERY parameter is used to indicate
to the Oracle database how much time to allow for instance recovery. Based on this
parameter, the Database Writer process will write to the database data files at a rate
that will try to match this target.
13. A, E. The diagnostic destination directory contains files that are used to diagnose and
correct database problems. Thus, the database trace files and the database alert log are
contained in this directory structure.
14. C. To back up a database in ARCHIVELOG mode manually, you would want to put the
tablespaces in backup mode. This is done most efficiently by using the ALTER DATABASE
BEGIN BACKUP command. You would then back up the database data files and then use
the ALTER DATABASE END BACKUP command to take all of the database data files out of
hot backup mode. Then you would need to perform an online redo log switch and then
back up the archived redo logs.
15. B, C. There are two kinds of backups. The first is a physical backup, which we discussed
in this chapter a great deal. The second is a logical backup, which we will discuss in other
chapters of this topic.
16. A, B, D. A valid database backup in NOARCHIVELOG mode requires that you back up
all of the database data files, the database online redo logs, and the database control files.
17. E. The V$DATABASE view column LOG_MODE indicates if the database is in
NOARCHIVELOG mode or ARCHIVELOG mode.