Re: When is anything written to standby redo logs on standby database

From: DA Morgan <>
Date: Mon, 15 Sep 2008 06:24:56 -0700
Message-ID: <> wrote:
> When is anything written to standby redo logs on standby database
> I am on Oracle on HP UNIX 11i. I have read Oracle 10.2
> concepts guide on, have read may article on
> metalink and internet, yet I am unable to verify when anything is
> written to standby redo logs on stand by database.
> I have a simple database reconfiguration: a primary database and one
> standby database.
> I created primary database and set up log_archive_dest_2 to use LGWR
> I have created standby redo logs on primary.
> alter database add standby logfile GROUP
> I create standby control file on primary.
> I copied all the primary information to create standby database. I
> have put standby database in managed recovery.
> I did archive log switches, I created a table and inserted information
> in table.
> I never saw standby redo logs updated on standby database by looking
> at timestamp of standby redo log files.
> I then setup database in maximum availability mode by running
> following on primary:
> Alter database set standby database to maximize availability
> When I do insert into my tables, I do see standby redo log files on
> primary database being updated, but I have never seen standby redo
> logs on standby database updated. Why?
> I am still at loss when actually standby redo logs are updated on
> standby database.
> When I read Oracle 9i database documentation on data guard, it says
> that you do not need standby redo logs on primary instead you need
> them on standby. Only reason, you need them on primary is from primary
> changes role to standby database, so standby redo logs on standby
> database should be updated instead of standby redo logs on primary.

When things are written depends on whether you are running in synchronous or asychronous mode. One is real-time the other when a log file switch takes place.

Daniel A. Morgan
Oracle Ace Director & Instructor
University of Washington (replace x with u to respond)
Puget Sound Oracle Users Group
Received on Mon Sep 15 2008 - 08:24:56 CDT

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