Re: When can I remove redo logs

I usually keep at least three days worth (in my case 2GB a day, I would prefer to keep 5 if possible).That way if you encounter a bad backup set(s) you can go back at least 4 backup sets and still do a recovery (assuming all log file and one of the last four hot backups backups are good) if necessary. For example:

|----------|---------|--------|--------|---------|

hb0         hb1         hb2        hb3       hb4       crash
lg0-1       lg0          lg1         lg2        lg3      lg4

hb= hot backup set point
lg= archive log backup set point

In this case, if I have lg 1-3 backed up and available I can go back as far as point hb1 and recover by applying hb1, lg1,lg2, lg3, and lg4 (archived logs since last hot backup). But, then again, I am a bit paranoid when it comes to preserving data.

M.Landa

Kurt Troyer wrote:

> I currently have a database running in Archivelog mode generating
> about 20 meg of redo per day. I am backing up the archived logs to
> tape, but would like to know when Redo logs are no longer needed. I
> have heard of starting a database with resetlog option. If I backup
> the database after starting with this option, do I need to keep the
> old redo logs?
>
> Kurt
Received on Sun Feb 08 1998 - 00:00:00 CST