Re: Redo logs only useful if archiving on

Redo logs are binary files (i.e. you can't read them with a text editor) that the database uses for recovery. They are divided into two types: online, and archived.

All databases require at least two online redo logs. You can (and probably should) have more. Theire fixed size is set at database creation, and oracle cycles through them. When one fills up, it switches to the next until it hits the last one, then it cycles back to the first.

Archived logs are created during this log switch process if you're database is in archivelog mode. All an archived log is, is an online file that's been copied to an archival directory (with a unique name) before it gets overwritten by the normal log cycling process.

All this should be documented in the Server Concepts manual. It's highly recommended reading.

        Chuck

On Sun, 28 Jun 1998 17:29:07 -0500, "DS" <ldcs3_at_mychoice.net> wrote:

>Help please. Redo logs, archive logs, online logs. Can you explain the
>difference to me? What about audit logs? Do they equal archive logs?
>Where are these logs located and how can they be accessed if needed? What
>Oracle reference manual provides this information?
>
>Thanks
>Diana
>
>Chuck Hamilton wrote in message <358d7fc1.3929145_at_news.dvol.com>...
>
>>You're confusing archived logs with online logs. The database still
>>needs online logs even if you're not in archive log mode. They'll be
>>used for recovery too if the required data is still in them.
>>
>>Cold backups are fine as long as you can afford to take your database
>>down. If you do switch to archive log mode, just remember to include
>>backing up and purging of archived logs as part of your
>>backup/recovery strategy.
>>--
>>Chuck Hamilton
>>chuckh_at_dvol.com
>>
>>If at first you don't succeed, sky diving isn't for you.
>

--
Chuck Hamilton
chuckh_at_dvol.com

If at first you don't succeed, sky diving isn't for you. Received on Tue Jun 30 1998 - 13:57:47 CDT