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RE: Disaster Recovery options

From: Ellis R. Miller <>
Date: Tue, 22 Mar 2005 09:28:38 -0600
Message-Id: <>


If you use Oracle Data Guard to set up a logical standby database (10G) where SQL from primary node is applied to secondary and the primary is an OLTP application then the secondary can/should be used for reporting.

Thus, where the pricing becomes more reasonable is in using the Data Guard architecture to ensure HA (failover) AND for a reporting architecture in which the primary node isn't getting pounded by long-running reports whilst high-concurrency transactional processing is occurring.

Generally, this pricing would be justifiable as from the standpoint of HA it is 24x7 high-concurrency, business critical OLTP applications that can afford the least amount of downtime, of course, and also require a separate reporting server. (I realize that many real-life environments like bringing the hardware to its knees by running resource-intensive reports or even batch processing even as millions of banking transactions are being processed and jeopardized but...)

Data Guard is infinitely improved over the former standby database architecture especially with regard to administration via OEM, instantiation without downtime, and, again, reporting.

A couple good references: pping.htm w.html

Hope that helps, some, and I am not sure Data Guard would be justified in your case or not but the reporting architecture, when considered with the HA advantages, does make the cost justification reasonable.


-----Original Message-----

From: [] On Behalf Of Brian Wisniewski
Sent: Tuesday, March 22, 2005 9:11 AM
Subject: Disaster Recovery options

I'm currently evaluating Data Guard for our DR setup and initial tests seem to work fine. However, I made the mistake of asking Oracle about the licensing of the failover machines and was shocked by their response.  

Here it is.  

Failover - In this type of recovery, nodes are configured in "cluster;" the first installed node acts as a primary node. If the primary node fails, one of the nodes in the cluster acts as the primary node. In this type of environment, Oracle permits licensed Oracle Database customers to run the Database on an unlicensed spare computer for up to a total of ten separate days in any given calendar year. Any other use requires the environment to be fully licensed. Additionally, the same metric must be used when licensing the databases in a failover environment. Standby - In this type of recovery, a copy of the primary database is maintained on a separate server at all times. These systems are configured for disaster recovery purposes. If the primary database fails, the standby database is activated to act as the new primary database. In this environment, both the primary and the standby databases must be fully licensed. Additionally, the same metric must be used when licensing the databases in a standby environment.

So I'm supposed to fully-license Enterprise Edition w/ RAC of course on a 2 or 3 node cluster sitting in a remote datacenter that isn't going to ever do anything unless there's a disaster? Oracle is pricing themselves right out of our shop if their licensing model continues. Anyone have know where I can find the Sqlserver-L mailing list?

How is Data Guard used in Oracle's defintions of a 'Failover'? Seems like you're using the same disks out of the cluster and Data Guard wouldn't even be used there?

I'm wondering if I should go with Oracle 10G standard Edition where possible w/ RAC since it's included in the license and then manually ship the logs up to a standby database instead of using Data Guard. Data Guard just seems to take care of the log shipment and applying for me. I haven't had a standby database since V7 but from what I've read it seems like I could manually ship and apply the logs using SE vs EE since 'Data Guard' isn't part of SE.

We have an SLA where a 4 hour data loss would be 'acceptable' so I don't think it would be too hard to write something to ship the logs and apply them if I have a 4-hour window to do it in.

Any input would be appreciated.

Thanks - Brian                 

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-- Received on Tue Mar 22 2005 - 10:33:59 CST

Original text of this message