Re: backups for Oracle. what mode was db created in?

Jeff Kish wrote:
>
> Regarding backups,
>
> 1. If a database was created with archivelog mode off, can we turn it
> on at a certain point in time to enable better recovery?

Yes.
SVRMGR> shutdown
Backup all of your db-files
Add INIT.ORA parameters LOG_ARCHIVE_DEST, LOG_ARCHIVE_FORMAT and LOG_ARCHIVE_START=true

SVRMGR> startup mount
SVRMGR> alter database archivelog
SVRMGR> alter database open

>
> 2. What is the best way to create a few extra control files for
> backup/recovery sake? We are using only one for one instance, and two
> for another instance. The two are in the same directory on the same
> disk. I assume ones on different disks are best.

Adding new controlfile:
SVRMGR> shutdown
copy current controlfile to new one
Modify INIT.ORA parameter CONTROL_FILES to include the new one SVRMGR> startup

You should place control files on physically different disks. If you have only one disk (should buy extra ones!) have multiple copies of control file. You can put them into different directories if you like.

>
> 3. I looked in the following tables to find out what database files
> are critical. How can I be sure of the init****.ora file being used? I
> assume that this file also should be backed up.
> select name from v$datafile
> select member from v$logfile
> select name from v$controlfile

When starting up the instance you can tell the INIT.ORA file to use by: SVRMGR> startup pfile=...
If you don't spesify pfile the Oracle will use file $ORACLE_HOME/dbs/init<SID>.ora (on UNIX at least).

-- 

Timo Haatainen
Carelcomp Forest Oy