Re: Status of online redo logs on the standby database

From: <>
Date: Mon, 18 Jan 2010 10:21:35 +0200
Message-ID: <>

You obviously went over this, didn't you:


from all that reading I got this bottom line:

Tune I/O subsystem, including some kernel parameters tweaking and

PARALLEL_EXECUTION_MESSAGE_SIZE = 64K I personally set PARALLEL_EXECUTION_MESSAGE_SIZE = 64K by default on all databases that have plenty of RAM.

Plus we had to tune SQLnet and TCP/IP related stuff cause LN.... waits were taking their share.

Please consider the environment before printing this e-mail

             Christopher Reeve                                             
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             oracle-l-bounce_at_f                                          cc 
                                       Status of online redo logs on the   
             2010.01.17 17:02          standby database                    
             Please respond to                                             

Hello listers
My first post...
I have a data guard environment running on on solaris 64. I have had some performance issues, on the standby side of things, concerning the rate at which redo is getting applied. Except for the disk subsystem, the box itself is bored. So I'm trying to figure out how to reduce the physical I/O. The environment itself is managed by the DG broker, and I have it set up to do real time apply, which works great most of the time, until we get to our batch processing periods, four times a month, then the standby begins to lag. One way of reducing I/O, I have read, is to NOT multiplex the standby redo logs. Certainly makes sense, with all the ways of getting redo over. While that did improve performance and reduce I/O, I'm still experiencing periods of lag. Is that enough background information? OK, on to the question...
With my situation, real-time apply, etc., I expected to see activity in v $standby_log, which I do. But I didn't expect to see activity in v$log, which I do. I have not seen any status here besides "CLEARING" and "CLEARING_CURRENT". So is this normal? If not, is this causing additional I/O that I can reduce further?


-- Received on Mon Jan 18 2010 - 02:21:35 CST

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