Comments on: Recovering Your Controlfile Without a Backup

By: Elbe

Elbe — Thu, 07 Aug 2008 21:21:10 +0000

…”Test the scenario where the the database is …even a RECOVER has been completed without an OPEN…”
Did this after failed recover w/o OPEN. I couldn’t query the database for the current redo log so I used the redo log with the newest date – it worked! This was not production but just me fooling around with renaming a test database. Still was cool learning experience.

By: suraj

suraj — Sat, 23 Feb 2008 07:36:04 +0000

Hi
But is it possible to use the RM control*.ctl, when the database is up and running.In windows this is not possible as it will not allow to delete the control file when it is in use.Anyways the scenario and the solution is awesome.
it will be really useful for inexperienced DBA who might have forgotten to include the contro file in their backup startegies..what say???

By: Monthly Blogroll Report (May 2007) « Coskans Approach to Oracle

Monthly Blogroll Report (May 2007) « Coskans Approach to Oracle — Wed, 30 May 2007 12:00:16 +0000

[...] whose previous entries are more related with RAC wrote interesting entries about scnarios of recovering controlfiles without backup , control file recovery of normal closed database with resetlogs and without resetlogs . I love his [...]

By: Controlfile Recovery WITHOUT Resetlogs : Ardent Performance Computing

Controlfile Recovery WITHOUT Resetlogs : Ardent Performance Computing — Tue, 15 May 2007 18:26:01 +0000

[...] last week I had a few posts about controlfile recovery; one about recovering without a backup and one about recovering with a backup using RESETLOGS. In the second post I showed how when you [...]

By: Hemant K Chitale

Hemant K Chitale — Fri, 04 May 2007 17:11:58 +0000

You didn’t actually “recover” the controlfile.
You really “restored” it.
You had done a shutdown abort of the database.
The datafiles were not in sync. The Recover command looks at all the datafile headers and realises that some datafiles are “ahead” of the others. The Recover command, then, DOES need an ArchiveLog (or the active online redo that hadn’t been archived yet — faking it is as an ArchiveLog).

You were testing a specific scenario where the controlfiles were deleted when the instance were running.

Test the scenario where the the database is shutdown normal/immediate (or even a RECOVER has been completed without an OPEN) — then restore or recreate controlfile and try a RECOVER. See if you can just do a CANCEL there.
Hemant

By: Don Seiler

Don Seiler — Fri, 04 May 2007 13:22:28 +0000

I was under the impression that as soon as a single copy of a controlfile was missing or corrupted, the instance would shutdown (presumably “abort”). I’ll have to test this on my sandbox.

Anyway, handy tip. Hope I never have to see it!