Re: Question re Physical and logical standby

From: jason arneil <>
Date: Tue, 14 Oct 2008 19:21:51 +0100
Message-ID: <>

Hi William,

I'd say this was pretty comprehensively dealt with in the oracle documentation,

to quote the relevant part:

"A LogMiner dictionary must be built into the redo data so that the LogMiner component of SQL Apply can properly interpret changes it sees in the redo. As part of building LogMiner Multiversioned Data Dictionary, supplemental logging is automatically set up to log primary key and unique-constraint/index columns. The supplemental logging information ensures each update contains enough information to logically identify each row that is modified by the statement."

To build the LogMiner dictionary, issue the following statement:

SQL> EXECUTE DBMS_LOGSTDBY.BUILD; This is done only on the primary.



2008/10/14 William Wagman <>

> Greetings,
> I'm running Oracle EE 64-bit on Windows Server 2003. I am
> performing these tasks from the command line rather than using the OEM. I
> have a physical standby for disaster recovery and now wish to create a
> logical standby to be used for reporting purposes. I have the second
> physical standby created and am preparing to transition to a logical
> standby. Two sources (Matthew Hart and Scott Jesse's book on High
> Availability and the technet article by Darl Kuhn,
> as the first step to enable supplemental logging on the primary via
> sql...
> SQL> alter database add supplemental log data (primary key, unique index)
> columns;
> Hart and Jesse say it should also be done on the standby whereas the
> technet article only mentions doing it on the primary.
> My first question, does this need to be run on the primary and both
> standbys, only the primary and the logical standby or only the primary?
> The Oracle documentation (chapter 4 of the Oracle Data Guard Concepts and
> Administration, 'Creating A Logical Standby Database') makes no mention of
> this but does mention building a dictionary in the redo data as follows
> My second question (point of confusion if you will), as I read the
> documentation it appears that these two approaches are actually different
> ways of doing the same thing, is that correct? If so and I choose to use
> DBMS_LOGSTDBY must that be run on the primary and both standbys, only the
> primary and the logical standby or only the primary?
> Thanks.
> Bill Wagman
> Univ. of California at Davis
> IET Campus Data Center
> (530) 754-6208
> --
-- -- --
Received on Tue Oct 14 2008 - 13:21:51 CDT

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