RE: Why extra standby redo log group?

Martin, John, Fuad,

Thank you. When you have heavy transaction for a period of time, if you have n log groups on primary and n+1 SRL groups on standby, do you see all n+1 SRL groups used? That is, on the standby, do you see all, not just n, rows in v$standby_log under status column, alternately showing 'ACTIVE'?

I know if I manually switch logfile on primary, only n SRL groups will be 'ACTIVE' (the extra stays unused). I'll test by building a small data guard where primary is on a node with fast storage and standby with slow storage and create lots of redo.

Yong Huang

• On Sun, 4/5/09, Martin Brown <martinfbrown_at_hotmail.com> wrote:

From: Martin Brown <martinfbrown_at_hotmail.com> Subject: RE: Why extra standby redo log group? To: john.hallas_at_morrisonsplc.co.uk, fuadar_at_yahoo.com, yong321_at_yahoo.com Cc: oracle-l_at_freelists.org
Date: Sunday, April 5, 2009, 8:46 AM

Totally agree. Our configuration has 8 primary nodes and (of course) only 1 standby node. For those that don't run DataGuard 10g, you can only have 1 active standby node. Normal log switches happen about 3 per hour. During peak times, our log switchs pick up speed and this configuration keeps up quite nicely.  

> From: John.Hallas_at_morrisonsplc.co.uk
> To: fuadar_at_yahoo.com; yong321_at_yahoo.com
> CC: oracle-l_at_freelists.org
> Date: Sun, 5 Apr 2009 14:33:16 +0100
> Subject: RE: Why extra standby redo log group?
>
> I would agree with what Fuad says, it is to ensure
that the standby can keep up with the primary. It is only a recommendation though and not mandatory
>
> John
>
> -----Original Message-----
> From: oracle-l-bounce_at_freelists.org
[mailto:oracle-l-bounce_at_freelists.org] On Behalf Of Fuad Arshad
> Sent: 04 April 2009 03:44
> To: yong321_at_yahoo.com
> Cc: oracle-l_at_freelists.org
> Subject: Re: Why extra standby redo log group?
>
>
> Well in my case I've seem standby redo logs used
to cover for backlogs I.e Log switching is faster than the standby instance can perform       

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