RE: Switchover of Logical Standby database

Date: Fri, 16 Dec 2011 18:16:01 +0000
Message-ID: <>

Are your clients configured with connect strings (jdbc or tnsnames) where both primary and standby sides are defied? Also is your app TAF compliant? And are you using Active Dataguard ? I suspect more a client configuration issue. I have seen funny behavior like this when older clients are connecting to new databases, or bugs in the client side. This is why one should make sure that the client is upgraded to the same level as the db. We have numerous configurations on 10g Dataguard, 1 primary and 2 standby, and the sessions re-establish to the correct primary database- however they are not TAF compliant so it requires a restart of the app.

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

From: [] On Behalf Of Gerry Miller Sent: Friday, December 16, 2011 12:24 AM To:
Subject: Switchover of Logical Standby database


I have had some experience with physical standby databases and the Data Guard broker but have recently been asked to implement a logical standby on on Windows 2008 Server. I was quite surprised to find that when a switchover or failover is performed that the databases are not shutdown, which results in a faster operation. However, I was perturbed to find that any sessions that were originally on the primary remained on the same database, that is, ended up on the standby database, when I would have expected them to be on the new primary. Queries can still be executed but any attempts at DML result in : "ORA-16224 Database Guard is enabled". This seems an unlikely situation and I can't help but feel that I must have something wrong with the configuration, although I can't imagine that it would work at all if that were the case.

Is this the expected behaviour or should the sessions have transferred during the switchover?



-- Received on Fri Dec 16 2011 - 12:16:01 CST

Original text of this message