Re: number of redolog groups

"Paul Drake" <drak0nian_at_yahoo.com> wrote in message news:1ac7c7b3.0311091122.68a345f4_at_posting.google.com...
> Sybrand Bakker <gooiditweg_at_sybrandb.nospam.demon.nl> wrote in message
news:<tqnsqvgifnuol37fhndhvcenkji205nh1v_at_4ax.com>...
> > On Fri, 07 Nov 2003 15:10:10 -0800, Daniel Morgan
> > <damorgan_at_x.washington.edu> wrote:
> >
> > >I see no point in having more than two groups.
> > >I see a lot of point in having more than two members to a group.
> > >Or am I having an attack of syntax dyslexia?
> >
> > You have.
> > There is no point in having more than two members.
> > There is a lot of point in having more than 2 groups, which is
> > largely determined by how write-intensive your instance is.
>
> what are the chances that HJR takes a bite out of this part:
> > There is no point in having more than two members.
>
> I'm thinking about 4 nines.
> He seemed to be preferential to 3 members per group.

True.

> As Oracle can use all available redo log members to feed the archiver
> processes, having more than 2 members per group could help to speed up
> archiving.
> (at the cost of LGWR having to write to multiple redo log group
> members).

Spot on. As you say, it's where you strike the balance on those cost-benefits.

> It goes back to "it depends".
> personally, I only use 2, except where there is a killer storage
> subsystem in place with more than sufficient IO capacity.
>
> Pd

Cheers. Said it perfectly.

Regards
HJR Received on Sun Nov 09 2003 - 14:10:15 CST