Re: Logical standby database in Oracle9i

From: Mark Bole <makbo_at_pacbell.net>
Date: Mon, 10 May 2004 15:41:03 GMT
Message-ID: <joNnc.65698$Z15.25503@newssvr25.news.prodigy.com>

Ryan Gaffuri wrote:

> "Howard J. Rogers" <hjr_at_dizwell.com> wrote in message news:<409dd70f$0$442$afc38c87_at_news.optusnet.com.au>...
> 

>>Prem K Mehrotra wrote:
>>
>>>I have read about logical standby databases and want to use it in
>>>my project for reporting.
>>>
>>>My main database instance will be using Oracle9i RAC, Reporting database
>>>instance may use only Oracle9i.
>>>
>>>Are there any issues with Oracle9i RAC to Oracle9i for logical standy.
>>> Also are there any issues from Oracle9i RAC to Oracle9i RAC.
>>
>>You mean, apart from the fact that logical standby has lots of bugs
>>associated with it, and doesn't actually work very reliably?
>>
>>No, none at all.
>>
>>Regards
>>HJR

> 
> 
> 
> What bugs? Are there bugs in dataguard in general?

DataGuard physical standby databases have been around for a long time and are pretty reliable.

Logical standby is much newer and doesn't seem to be robust enough to use as a first choice for disaster recovery. For example, if you drop a user and then re-import on the primary, including lots of constraints, sequences, triggers, packages and procedures, in my tests the logical standby eventually stalled out to the point where it was easier to just re-create it than try to cajole the SQL apply to complete successfully.

But logical standby might be just the thing for other uses besides disaster recovery. If you have ever implemented a physical standby so that you could open it read-only from time to time, then logical standby   might better meet your needs.

Be sure to get the white paper from Metalink "Oracle 9i Dataguard: SQL Apply Best Practices". I found several items there, not included in the main documentation, which resolved some bugs I was experiencing.

--Mark Bole Received on Mon May 10 2004 - 10:41:03 CDT