RMAN recovery using a backup Control File and RESETLOGS concepts [message #244574] |
Wed, 13 June 2007 06:50 |
patrick_tahiri
Messages: 3 Registered: April 2007
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Junior Member |
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It's about the Oracle DBA course:
Oracle 9i – FUNDAMENTAL II side 17-16:
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Use the RESET DATABASE command:
A. To direct RMAN to create a new database incarnation record.
B. To distinguish between opening a database with RESTLOGS and an accidental restore operation of an old control file.
If the target database is recovered to a point in time in the past, the DB must be opened with the RESTETLOGS option. In this case, RMAN cannot use the recovery catalog again until a RESET DATABASE is issued.
This enables RMAN to distinguish between RESETLOGS and an accidental restore operation of an old control file (*1).
C. Open with RESETLOGS after RESET DATABASE
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Questions:
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Pt. B: (*1) What is the difference for RMAN between a recovery to a point in past and a restore of an old Control File? What RMAN has to distinguish between RESETLOGS and “an accidental restore operation of an old control file”?
. Doest it mean at RESET DATABASE concept is to let know RMAN the differences between opening a database with RESETLOGS and opening a database using an old backup Control File?
We have to use RESETLOGS anyway if we are restoring and recovering a database using a backup Control File…
· What do they mean with “accidental restore operation of an old control file”?
==>> An old control file has been restored by accident, instead to not restore them and leave the current ones (not lost or damaged)?
OR
==>> An old control file has been restored because of the accidental loss of all the current Control files (must restore them from an old backup)?
· What would happen if we had to restore them?
==>> Open database with NO RESETLOGS and NO RESET DATABASE (Rman prompt)?
OR
==>> Open database with RESETLOGS but NO RESET DATABASE (Rman prompt)?
· What if we missed all Control Files but all Datafiles, Archived Redo Log file, and Online Redo log files are available: isn’t strange and inconsistent to restore an old Control File from a backup and open the database with RESETLOGS and so wiping out and missing all the last changes/transactions in the current Online Redo Log file? Even if we didn’t miss any data… This would be a real pity having all the data and must execute a RESETLOGS loosing the last changes…
Pt. C: Shouldn’t we open with RESETLOGS before to RESET DATABASE at the RMAN prompt??
Thank you in advance for your help!
Best regards,
Patrick.
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