Re: Oracle 10 Failover

From: DA Morgan <>
Date: Wed, 10 Sep 2008 19:34:25 -0700
Message-ID: <> wrote:
> On Wed, 10 Sep 2008 20:44:47 +0200, "Chris Seidel" <>
> wrote:

>> wrote:
>>> I wouldn't consider client side failover using any form of
>>> replication.
>> Why not if the data doesn't have to be "brand new"?

> I already explained Streams and CDC are asynchronous. This means
> transaction consistency is NOT guaranteed. Dataguard potentially
> guarantees transaction consistency.
>>> Client side failover applies to Dataguard or RAC, not Streams or CDC.
>> RAC uses a single database. So RAC alone is not an option for a distributed 
>> environment. In a distr. env. I need RAC + Data Guard, right? 

> Are we discussing a distributed environment? As far as I am concerned
> we are discussing misusing distributed multi-directional technologies
> (replication, streams) to mimic unidirectional fallback technologies
> (Dataguard).
> The main purpose of RAC is to protect servers (and to offer additional
> scalability).
> The main purpose of Dataguard is to protect disks.
> I do not see where distributed environment comes into play, nowhere
> you described you have a distributed environment.

A few small corrections. Streams can be set up synchronously or asychronously. Data Guard does guarantee zero data loss when configured synchronously ... maximum protection mode.

Chris: Define what you mean by "distributed environment." The term is subject to different interpretations by different people.

Daniel A. Morgan
Oracle Ace Director & Instructor
University of Washington (replace x with u to respond)
Puget Sound Oracle Users Group
Received on Wed Sep 10 2008 - 21:34:25 CDT

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