log_archive_max_processes in DG

From: Kumar Madduri <ksmadduri_at_gmail.com>
Date: Thu, 2 Jul 2009 09:21:25 -0700
Message-ID: <a2b1e7610907020921k5c96bfa0q1743ec222263ec5c_at_mail.gmail.com>

I have seen several examples of Data Guard setup where log_archive_max_processes is set at 30. But I read that setting these to high values can cause memory issues. Oracle documentation on this parameter also says the default of 2 should be fine for most cases. What should this number be set when you are setting up Data Guard?

The LOG_ARCHIVE_MAX_PROCESSES initialization parameter specifies the number of ARCn processes that the database initially invokes. The default is two processes. There is usually no need specify this initialization parameter or to change its default value, because the database starts additional archiver processes (ARCn) as needed to ensure that the automatic processing of filled redo log files does not fall behind.

However, to avoid any runtime overhead of invoking additional ARCn processes, you can set the LOG_ARCHIVE_MAX_PROCESSES initialization parameter to specify up to ten ARCn processes to be started at instance startup. The LOG_ARCHIVE_MAX_PROCESSES parameter is dynamic, and can be changed using the ALTER SYSTEM statement. The database must be mounted but not open. The following statement increases (or decreases) the number of ARCn processes currently running:

ALTER SYSTEM SET LOG_ARCHIVE_MAX_PROCESSES=3;* Also another related question is about Standby Redo Logs. If you are planning to set the DG in max performance mode, would there be any advantage in adding SRL? I undertand that having SRL will give the ability to have the lates online redo log info in SRL and decreases my recovery time. But if that is not a criteria , would I be better off without adding SRL (From a performancce point of view).

Thank you
- Kumar

Received on Thu Jul 02 2009 - 11:21:25 CDT

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