RE: Change based recovery

[Fermin Bernaus]

 

    I've been reading your messages with much interest. I have some experience with database administration and I have done many tests, but I've not tried what I am going to expose in this message, maybe you can help. We do cold backups on a regular basis (every weekend) then just backup the archive log every day, then delete them every time a new cold backup is done. We have tested it and if all database files (parameters file, datafiles, control files) except for one control file and the archived logs were lost we could recover the entire database issuing the following commands after restoring all missing files and mounting the database:

 

    SET AUTORECOVERY ON

    RECOVER DATABASE

    ALTER DATABASE OPEN

 

    My questions are:

 

    1 - Could a complete restore be done even if we lost ALL control files? can we recover the entire database from a cold backup provided we have all archived logs until the failure time?

    2 - If the answer is yes, what is the advantage of doing on-line backups of datafiles and control files?

 

    Thanks for your answers, I always learn so much from this list!!

 

Fermin.

-----Mensaje original-----
De: Hand, Michael T [mailto:[EMAIL PROTECTED]
Enviado el: viernes, 08 de agosto de 2003 18:10
Para: Multiple recipients of list ORACLE-L
Asunto: RE: Change based recovery

Lisa,

The 3rd option (besides shuting down source database and using a controlfile trace) is to "alter database backup controlfile to 'filename'; ", use this file, then proceed with the recovery as Venu suggests.  I've used this method on a hot backup to roll the database forward.  Also, don't bother restoring the redo logs as you will be overwriting / recreating them with the "alter database open resetlogs".  One more thing I noticed.  Your until change number looks to me like an archive sequence number rather than the SCN it needs to be.  Hope this helps.

 

Mike Hand

-----Original Message-----
From: Dobson, Lisa [mailto:[EMAIL PROTECTED]
Sent: Thursday, August 07, 2003 8:21 AM
To: Multiple recipients of list ORACLE-L
Subject: Change based recovery

Hi Guys and Gals,

We are currently doing some testing to enable us to move our production database from one unix box to another.

We are running a 7.3.4 db in archivelog mode.  The approach that management want to use is to restore the database on the new server from a backup and then roll it forward using the archived redo logs.

 

I have a full cold back up from last Friday. I have restored the datafiles, controlfiles and redo logs onto our test server from the backup tape, and then ftp'd the archived logs over.

 

I then do -

SVRMGR> startup mount
ORACLE instance started.
Total System Global Area     258304260 bytes
Fixed Size                       45092 bytes
Variable Size                126925024 bytes
Database Buffers             131072000 bytes
Redo Buffers                    262144 bytes
Database mounted.
SVRMGR> recover database until change 10349;
Media recovery complete.