RE: Manual Standby as alternative to dataguard

From: Ric Van Dyke <>
Date: Tue, 16 Jun 2009 15:07:08 -0500
Message-ID: <>

The apply process will apply what ever it gets from the primary. If there are data integrity issues, then you will have to sort that out when you try to active the standby.  

So the answers to your direct questions are NO and NO.  

Like Jared said, this is not a technical issue. Dataguard will run just happy as a pig in slop no matter what the setting of FORCE LOGGING on the primary. You just might not be able to use the database when you try to active it if it's not turned on. If they want to run with out turning on FORCED LOGGING then they are kidding them selves about having a DG site. And you and your IT staff better have that in writing so they don't think they do have a DG site when they really don't.  

How much stuff is running with NOLOGGING anyway? And does everyone really know what NOLOGGING does? It may not be doing what they think it is doing anyway.  

Ric Van Dyke

Hotsos Enterprises


Hotsos Symposium

March 7 - 11, 2010

Be there.    

[] On Behalf Of sanjeev m Sent: Tuesday, June 16, 2009 3:45 PM
To: Mathias Magnusson
Subject: Re: Manual Standby as alternative to dataguard  

They are expecting performance issues. I agree this has to be tested with them after enabling it in non-production evironment and if there are still performance issues really then move off those segments to a different tablespace,Enable force logging for the rest of the tablespaces atleast.We will set the expectation with business that those objects with nologging cant be recovered on activation of standby

My question is  

(*) will the Dataguard managed recovery itself have any issues if there
is noforce logging on primary?

(*) In other words is there any difference in implementing using manual
method versus Dataguard (MRP) with nologging as long as there is no impact to log apply(recovery) on standby.  

On Tue, Jun 16, 2009 at 11:59 AM, Mathias Magnusson <> wrote:

What kind of problem does the business see with force logging? What transactions do you have that they require nologging on that is critical to the business?  

That is, are you fighting a theoretical or real problem? Force logging is that because it is needed. You cannot invent data that is now written to the log files. Manual or not, you'll have the same need to have logging occur.  

I think you are better off dealing with the actual issue, rather than something that seems to an opinion not based on hard data.


On Tue, Jun 16, 2009 at 8:41 PM, sanjeev m <> wrote:


At our site we are having difficulty getting approval from business to enable force logging on database objects.  

We plan to implement DR using manual method ie (shipping archive logs to DR site through cronjob, performing manual recovery on mounted standby controlfile)  

I understand without forcelogging all nologging transactions wont be recoverable. Is this true during recovery or after activating the standby?  

Is forcelogging a mandatory pre-requisite for implementing Dataguard? Has any of you have experience implementing Dataguard without force logging enabled.  

Will there be any issues during managed recovery if it encounters a nologging change? Wont we be hitting same issue if we are doing the recovery manually as opposed to MRP process?  



Received on Tue Jun 16 2009 - 15:07:08 CDT

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