Re: archive logs grow too fast

Hi!

And don't forget, that your redo generation might hit the ceiling when you do maintenance work such as deleting a lot of old data from your tables.

Tanel.

"Mark D Powell" <Mark.Powell_at_eds.com> wrote in message news:2687bb95.0302270713.7a8cc537_at_posting.google.com...
> usenet_at_sein.sportwetten.spb.ru (Oleg Paraschenko) wrote in message
news:<70f723dc.0302262137.514b54ab_at_posting.google.com>...
> > Hello all,
> >
> > I'm interesting if there are method to calculate disk space required
> > for archive logs. High accuracy is not required. I will be grateful
> > for any recommendations how to start to investigate what and why I
> > have in archive logs.
> >
> > Regards, Oleg
>
> Oleg, if you system is already built and in archive log mode you could
> query v$archived_log and calculate how much data you are writing. If
> your system is in noarchivelog mode then this veiw is empty, but you
> can count the number of log switches in the alert_sid.log and multiple
> by the defined log size.
>
> set echo on
> select
> sum(blocks)
> from
> v$archived_log
> where trunc(completion_time) = trunc(sysdate - 1)
> /
>
> SUM(BLOCKS)
> -----------
> 705994
>
> select 705994 * 512 from dual
> /
>
> 705994*512
> ----------
> 361468928
>
> The block size came from v$archived_log.
>
> If your system does not yet exist then you have to resort to
> estimating how much DML activity your database is going to experience.
> In general I want to size my redo logs such that 24 to 48 logs per
> day are archived. That is an average of 1 every half-hour to hour.
>
> HTH -- Mark D Powell --
Received on Thu Feb 27 2003 - 10:21:41 CST