RECOVER DATABASE starts with an update -- 2

Continuing my previous post where I showed that a RECOVER DATABASE USING BACKUP CONTROLFILE starts with an Update

I STARTUP MOUNT the database :

ora10204>sqlplus '/ as sysdba'

SQL*Plus: Release 10.2.0.4.0 - Production on Fri Jun 4 22:55:11 2010

Copyright (c) 1982, 2007, Oracle.  All Rights Reserved.

Connected to an idle instance.

SQL> startup mount;
ORACLE instance started.

Total System Global Area  880803840 bytes
Fixed Size                  2087992 bytes
Variable Size             218104776 bytes
Database Buffers          654311424 bytes
Redo Buffers                6299648 bytes
Database mounted.
SQL>  

From another session, I check the type of controlfile :

SQL> select controlfile_type from v$database;

CONTROL
-------
CURRENT

SQL> 

So, the controlfile "type" is "CURRENT" , this really being the current controlfile.

I then issue my RECOVER .. USING BACKUP CONTROLFILE command :

SQL> recover database using backup controlfile until cancel;
ORA-00279: change 3632262 generated at 06/04/2010 22:54:20 needed for thread 1
ORA-00289: suggestion :
/oracle_fs/FRAs/ORT24FS/ORT24FS/archivelog/2010_06_04/o1_mf_1_1_%u_.arc
ORA-00280: change 3632262 for thread 1 is in sequence #1


Specify log: {=suggested | filename | AUTO | CANCEL} 

I then re-check the type of controlfile :

SQL> select controlfile_type from v$database;

CONTROL
-------
BACKUP

SQL>

Aah ! The Controlfile itself has been updated and is now a BACKUP file, not the CURRENT file.
This will be the status regardless of whether ReCOVERy succeeds or fails.

CANCEL
Media recovery cancelled.
SQL> 

From the other session :

SQL> select controlfile_type from v$database;

CONTROL
-------
BACKUP

SQL> 

Can I open the database, knowing that no file are inconsitent (had files been inconsistent, I would have recived a warning "file %s needs more recovery") :

SQL> alter database open ;       
alter database open
*
ERROR at line 1:
ORA-01589: must use RESETLOGS or NORESETLOGS option for database open


SQL> 

The status remains a BACKUP :

SQL> select controlfile_type from v$database;

CONTROL
-------
BACKUP

SQL> 

Since I cannot OPEN without resetting logs when I have a Backup Controlfile (the RESETLOGS will synchronise the controlfile with the "latest" current information from the Datafiles, even as updated by application of Redo (if any)), I must RESETLOGS :

SQL> alter database open resetlogs;

Database altered.

SQL>  

The status now is CURRENT:

SQL> select controlfile_type from v$database;

CONTROL
-------
CURRENT

SQL>  

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