Controlfile Recovery Requires RESETLOGS
- From: "Jeremy Paul Schneider" <jeremy.schneider@xxxxxxxxxxxxxx>
- To: oracle-l <oracle-l@xxxxxxxxxxxxx>, "Hemant K Chitale" <hkchital@xxxxxxxxxxxxxx>, "Joel.Patterson@xxxxxxxxxxx" <Joel.Patterson@xxxxxxxxxxx>, "Mark W. Farnham" <mwf@xxxxxxxx>
- Date: Wed, 9 May 2007 14:49:08 -0500
Hey all...
In response to a bit of discussion last week - I put together the test and
output showing how controlfile recovery requires recovery and a RESETLOGS
even if the database was closed normally, in a consistent state. I posted
the output here:
http://www.ardentperf.com/2007/05/09/controlfile-recovery-requires-resetlogs/
=====
Most questions can be answered by looking at the post since I walked through
the whole process. But to answer a few specific questions that various
people asked...
On 5/4/07, Mark W. Farnham <mwf@xxxxxxxx> wrote:
1) Did you shut down just the database or the whole machine?
In this test I only shut down the database however it was completely
shutdown and I would anticipate the same results with a machine reboot.
2) Did you let Oracle complete the shutdown immediate, or did you
kneecap any processes, especially including LGWR (log writer, whatever name
it goes by on your release)?
Yes Oracle completed the shutdown immediate - it was a clean shutdown. I
didn't kneecap anything.
3) Is any sort of write cache enabled on the devices supplying the
persistent media for your redo logs or controlfiles?
Shouldn't be relevant for this test. The OS and storage subsystem were
never interupted; I simply shutdown Oracle (normal) then removed the control
files and restarted it.
4) Did you replace the current controlfile with anything else?
Nope. Just deleted it.
5) Did you use the recover command with … using backup controlfile?
Yes - oracle required the "using backup controlfile" clause.
On 5/4/07, Joel.Patterson@xxxxxxxxxxx <Joel.Patterson@xxxxxxxxxxx> wrote:
Even if you switched current, or all before shutdown?
In the test I posted online I tried with a log switch before shutdown. I
would anticipate that this has no impact either way on the RESETLOGS.
On 5/4/07, Hemant K Chitale <hkchital@xxxxxxxxxxxxxx> wrote:
Question : In your recovery testing, what was the exact sequence ? Was
it ?
a) Restore an older controlfile binary backup -- only
controlfile restored, datafiles being current
b) Issue RECOVER DATABASE USING BACKUP CONTROLFILE -- did you
also specify "UNTIL CANCEL" ?
OR
a) Create Controlfile
b) Issue RECOVER DATABASE ... commands.
The first - I restored a binary backup.
--
Jeremy Schneider
Chicago, IL
http://www.ardentperf.com/category/technical
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