Full backup + archive logs = redundant? [message #402424] |
Sun, 10 May 2009 04:35 |
Joppybt
Messages: 7 Registered: May 2009
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Junior Member |
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Our database is not very big (2GB) so we can run a full on-line backup every night at 3 AM.
Do we actually *need* to include the archive-logs with that backup to be able to restore the database?
If I understand correctly the archive-logs would only be necessary after restoring the *previous* backup and recover it up to date. Hence the redundancy: either restore the latest backup directly or use the previous backup with all archive-logs.
Is this correct?
The only advantage I see in using the archive-log is that they would allow recovery to any point-in-time in the past day?
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Re: Full backup + archive logs = redundant? [message #402431 is a reply to message #402428] |
Sun, 10 May 2009 07:18 |
Joppybt
Messages: 7 Registered: May 2009
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Junior Member |
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So, just for my understanding:
- At the start of the backup RMAN does not necessarily care about previously archived logfiles (they are committed in the datafiles anyway)
- At the end of the backup RMAN will force a log-switch and RMAN needs to include the few archived logfiles since it started, including the last one that just switched.
This way the backup will allow restore+recover to the end-time (3:30AM) of the backup, not to the start-time (3:00AM).
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Re: Full backup + archive logs = redundant? [message #402440 is a reply to message #402431] |
Sun, 10 May 2009 09:06 |
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Michel Cadot
Messages: 68716 Registered: March 2007 Location: Saint-Maur, France, https...
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Senior Member Account Moderator |
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If you want to be sure to be able to restore and recover at the time of the end of the backup, you must checkpoint and switch current log, note it which one it is, backup datafiles, switch and archive current log, backup the archived logs between the 2 and including them.
Now this assuming you want no more than one backup. Of course, if your backup is corrupted or lost for any reason, you have no backup.
Regards
Michel
[Updated on: Sun, 10 May 2009 09:08] Report message to a moderator
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