Re: Oracle SE and Standby database...

  • From: Carel-Jan Engel <cjpengel.dbalert@xxxxxxxxx>
  • To: drp4kri@xxxxxxxxx
  • Date: Tue, 23 May 2006 01:27:51 +0200

Hi Dhimant,

This is doable. I have done this several times, most of the times using
scripts to forward redo and so on.

Start defining the requirements for your database (together with
business/mgmt). Recovery time required? Data loss allowed? and so on.
What OS are you on?

If you are on Windows you might look at Niall Litchfields scripts:
http://www.niall.litchfield.dial.pipex.com/scripts/dr/DR.zip
Another option, for Solaris, HP-UX or Linux (not free) can be found at
http://www.avisit.co.nz
 
I must say that I haven't been able to test either of these. For dbvisit
a trial license is available. Niall's work is licensed under the common
creative license.

I have several customer running 'ordinary' log shipping, AKA 'Vanilla
Standby'. Some of them are big enterprises, however, the system involved
just can afford an hour or so of data loss, and recovery within 30 - 60
minutes is OK for them. So, they don't bother buying EE with Data Guard.
The Vanilla Standby works fine.

The three step schema you mention is well defined. It's about how to
keep the standby up to date. Then you have to cover for temporary
network outages: how to close the gap of redo seq# that will get created
then? How to monitor that the standby isn't lagging behind too much,
creating potential data loss? When and how to failover? How to restore
the original situation with a Standby again? Mind that after a failover
your data is more vulnerable than ever: you are in an unusual situation,
and there is no Standby available. Mind that having a Standby is NEVER a
replacement forhaving a backup! Have proper backup gear available at the
Standby site as well!

You are totally right, it is more complex than just the three steps.
However, your awareness of this is a great gift. Lot's of people thought
it is simple, jumped into solutions and learned it the hard way.

About your license: Do you have SE or SE-one? I think SE-one is enough,
if your server can install 2 CPUs at max). If you have Named User Plus
type licenses for SE-one you need at least 20 licensed users to allow
for a standby database running at another 2-CPU server. If you have 20
NUP users already (5 is the minimum per CPU) you don't need extra
licenses.  If you license per CPU you need additional licenses for your
standby server as well.

Please note I'm not a lawyer. I do not take any responsability for the
advice, check with your lawyer and/or Oracle Sales. Details about
licensing can be found in
http://www.oracle.com/corporate/pricing/sig.pdf
This link is very useful in discussions with Oracle Sales. I have 'won'
several discussions with the nice sales-guys, saving some customers
100's of K's of euro's. Just being prepared, and knowing the rules as
defined in the SIG helps a lot in this 'game'.

Best regards,

Carel-Jan Engel

===
If you think education is expensive, try ignorance. (Derek Bok)
===


On Mon, 2006-05-22 at 17:33 -0400, Dhimant Patel wrote:

> Hi ALL!
> This is indeed my first mail but since last sometime I enjoyed reading
> conversations and ideas presented on this mailing list.
> 
> 
> 
> Here is my small :-) problem. We are a small company with tight budget
> and I need to come up with Oracle standby database for our 2 CPU SE
> license. Any ideas? I read good amount of documentation 
> and it references that it is possible - I want to put this into
> production. 
> 
> From what I can follow:
> 
> 1. You have a production db running on Oracle SE.
> 2. Create an SE db on different server, run it in standby recovery
> mode. 
> 3. Copy log files from production to standby server and apply logs.
> 
> 
> Although when you follow it deeper it doesn't sound so simple.
> Consideration must apply towards keeping uniqueness of the data
> between the DBs and so now you are adding one more 
> level of complexity and a whole lot of configuration. 
> 
> As already mentioned - I am just exploring and may come up with some
> simpler mechanism to implement this - hopefully. 
> 
> Has anyone done this?
> What is the best approach for small organizations to achieve 99.9%
> availability while keeping cost down? 
> Could RMAN help?
> 
> 
> 
> Thanks,
> Dhimant Patel.


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