Re: dbstart -- file 'xx' needs media recovery

From: Mark Bluemel <markb_at_pyramid.com>
Date: 1995/09/11
Message-ID: <1995Sep11.080217.699_at_pyra.co.uk>#1/1


Saad Ahmad (sahmad_at_mfa.com) wrote:
: The machine ( HP 9000) running HP-UX and Oracle 7
 

: When the machine rebooted oracle did not start and
: it said that file 'xxx' needs media recovery.
 

: The media was fine. I did an
: alter database recover data file 'xxx';
 

: and database was mounted ok.
 

: the only odd thing that happened was that
: the data file that oracle was complaining about was
: being backed up and END BACKUP was not done on it
: when a kill -9 was done for the backup job; but
: Oracle should have been able to recover in that case ???

This sounds about right to me. Each data file has a note of the current redo log file sequence number in its header. This is compared with the current redo log file sequence number in the control file at database startup.

If the control file has a later sequence number than the datafile, then the data file needs recovery. (If the control file has an earlier sequence number then there's something badly wrong :-) ).

BEGIN BACKUP suppresses the updating of the log file sequence number when a "Checkpoint" occurs. So given that a checkpoint (redo log file filling and a new one being started) occurred during your online backup, the sequence in the file header was before that in the control file - so ORACLE asked for a media recovery.

--
Mark Bluemel	Unix/Oracle Trainer and Consultant
		My opinions are my own, but I'll share them
		All solutions to problems are offered "as is"
		and without warranty - you have been warned :-)
Received on Mon Sep 11 1995 - 00:00:00 CEST

Original text of this message