A database is configured in ARCHIVELOG mode.
Full RMAN backups are taken daily and no backup to trace has been taken of the control file.
A media failure has occurred.
In which two scenarios is complete recovery possible? (Choose two.)
A database is configured in ARCHIVELOG mode.
Full RMAN backups are taken daily and no backup to trace has been taken of the control file.
A media failure has occurred.
In which two scenarios is complete recovery possible? (Choose two.)
Complete recovery in a database configured in ARCHIVELOG mode relies on having access to all necessary redo logs since the last full backup and the control files. Losing an archived log from after the most recent backup would prevent complete recovery because the redo information is missing. Thus, losing an archived log from before the most recent backup does not hinder recovery because the changes would already be captured in the backup. Similarly, the loss of the SYSTEM tablespace can be recovered from the backup and logs. Therefore, complete recovery is possible in these scenarios.
de b will do a resetlogs
i think D and E are correct. If you lose any archive from after the backup, you can't do a complete recovery, so A and C are discarted, also you can't mount the database if you don't have a valid control file. (not B)
what if the questions is incomplete recovery, what do you think the answer? I think C,D are correct, what's your idea?
well if the question was "incomplete recovery" then i think that you only need the control file and the backup, so it could be possible to do the incomplete recovery in A,C,D, and also E, fortunately they ask for the complete recovery scenario, so i'm going with D, E :)
You cannot open a DB when recoverd using backup controlfiles. RESETLOGS is required (in-complete recovery).
B and D thegeekstuff.com/2014/11/oracle-rman-restore/ This is a complete recovery even though the database is opened with resetlogs option: RMAN> STARTUP NOMOUNT; RMAN> RESTORE CONTROLFILE FROM "/backup/rman/ctl_c-12345-20141003-03"; RMAN> RESTORE DATABASE; RMAN> RECOVER DATABASE; RMAN> ALTER DATABASE OPEN RESETLOGS;
if only non default parameter CONFIGURE CONTROLFILE AUTOBACKUP ON or you have taken your backup using following command RUN { BACKUP DATABASE; BACKUP SPFILE; } # or if your database does not use a server parameter file: RUN { BACKUP DATABASE; BACKUP CURRENT CONTROLFILE; } but we do not know that ...
DE Complete Recovery Apply online or archived redo logs, or a combination of the two In this case, we need choice C to do complete recovery Incomplete Recovery you do not apply all of the redo records generated after the most recent backup. https://docs.oracle.com/cd/B13789_01/server.101/b10743/backrec.htm
B is a weird one. If autobackup is ON, we would have an extra backup piece for the control file in the backupset. (for CDBs and non-CDBs, starting with 12.0.0 or higher, autobackup is turned on) Even if autoback is OFF, then, when we issue a BACKUP DATABASE or BACKUP TABLESPACE that includes data file 1 (system), then by default oracle includes the control file as part of the backup, but not as a separate backup piece. https://docs.oracle.com/en/database/oracle/oracle-database/19/rcmrf/BACKUP.html#GUID-73642FF2-43C5-48B2-9969-99001C52EB50 Why i would say B is wrong is because we somehow lost "ALL copies of the control files"
Control File is not involved in media recovery Complete recovery needs backup + archivelogs to recover DB/TBS
DE correct
i think de
All other situations will either deprive you of some transactional information }current or archived redo logs to redo the transactions up to date) or you do not have current LSN to complete the recovery (as the LSN is written in the controlfile header).
DE correct sure
A - FALSE of course - database recovery is possible ony to SCN with, the last transaction in previous archivied redo log, B - TRUE/FALSE because we do not know how the backup was taken, C - FALSE (no any doubts), D - TRUE (no any doubts), E - TRUE (because we can restore full database),
DE, also B is correct. Full backup includes controlfile even without CF copy so it can be restored from there...
B is correct if CONFIGURE CONTROLFILE AUTOBACKUP is set to ON.
If controlfile need to restore from autobackup, it may not be the latest version. In such case, should it be in-complete recovery instead of complete recovery?