Re: HOT Backups - Online Backups

The redo log files are backed up automatically by running the database in ARCHIVELOG mode. This mode tells Oracle to back up a redo log file before reusing it. (Redo log files are used in a circular fashion.) You should also use a redo log group consisting of more than one file. This is the same as doing mirroring on the redo log files. This ensures that your current redo log file also has multiple mirror copies.

Copying the datafiles gives you the latest snapshot of the data before backup begins. In case of a crash, you can recover this snapshot, then apply the redo logs to roll forward to the latest state.

Cheers,
Dave

Hari Om wrote:
> I was reading a book on Oracle Backup and Recovery.
> As per the book, to perform HOT BACKUP we use folloeing steps:
> 1)SQL>alter tablespace ts1 begin backup;
>
> 2)Copy all the datafiles that a part of ts1 tblspc.
> SQL>host cp /u10/appl/oracle/oradata/d.dbf u10/appl/oracle/backup
>
> 3)SQL>alter tablespace ts1 end backup;
>
> 4)SQL>alter database backup controlfile to
> /u10/appl/oracle/back/control;
>
> This shows it is only BACKING UP DATA and CONTROL files. Then WHAT
> ABOUT THE REDO LOG FILES? Do we NOT need to back those up as well?
>
> Correct me if I am wrong. Any related informatino on this is
> appreciated.
>
> Thanks!
Received on Wed Aug 06 2003 - 15:55:16 CDT