Re: Questions about applying archive logs

"Hub" <hub_at_houston.rr.NOSPAM.com> wrote in message news:NEsq9.125210$8o3.3755846_at_twister.austin.rr.com...
>
> Howdy ya'll..

Let me guess. You're from India ;)

I have some archive log questions. Oracle 9i, linux,
> standard edition.
>
> Ok our main prod server spits out archive logs. On a seperate standby
> server I have copies of all the cold backup files.. tablespace, logs,
> control, redo, etc.. Every 15 minutes I cron job rsync the archive logs
to
> the standby server. What should I do on the standby side to automatically
> apply these archive logs to the standby server as they arrive (or soon
> thereafter)?

OK. Recommendation 1. Lookup the Data Guard Concepts manual and see if Oracle's Data Guard (or Standby DB) is the way to go. Based on what you've requested to do, I would suggest it is as everything can be nicely automated and protected.

So you need to create the standby DB on your standby server (basically copying the database files across, a special standby control file that's initially created on the prod server and possibly creating a set of standby redo log files). Then mount the database and put it in managed recovery mode which will make the standby DB applied redo as and when it arrives.

On the Prod DB, the log_archive_dest_n parameters have options that enables Oracle to automatically transport the redo to the standby server via either the ARCH or LGWR processes.

> Then if for some reason we have to switch from the main prod
> server to the standby one.. what is the appropriate technique/syntax to
take
> the latest archive/redo files, apply them to the standby box, bring the
> database up on the standby server.. etc.. does the main prod server have
> to be down to do this or can it still be running?

OK. Recommendation 2. Lookup the Data Guard Concepts manual and the various options you have. You can either perform a graceful switchover which enables you to swap the behaviours of the Prod/Standby database (and very easily back again) or you can simply activate the standby DB which converts it to the 'Mainman'.

>
> Also, how can i have this standby database be read-only, updated as the
> latest archive logs arrive, used for a report server..

OK. Recommendation 3. Lookup the Data Guard Concepts manual and see how you can take the standby DB out of recovery mode and open it as read only. At this point, users can log on and execute their queries but of course the database is no longer being maintained as such. But that's fine, any queries that only requires historical data and isn't too fussed about having today's data will be as happy as Larry. Then you can kick everyone off and place the standby db back in recovery mode. Note that a Temp LMT is crucial here but the Data Guard doco covers all of that.

>
> Also these archive logs, can I apply them to another database somehow?
Just
> pick an archive log file and say "try to apply all of these changes to
this
> database"?

Yes. You can create a "clone" database (which you create from the backups of the Prod DB) and use the archive logs created since the backup to get the clone as up to date as required. Note the database must be a clone database, it can't just be any database for (I hope) obvious reasons.

My last recommendation. Read up on Data Guard. There's a lot to Standby DBs these days with many options that make what you appear to want to do very flexible and automated.

Good Luck

Richard

>
> thx a bunch.. Hub
>
> hub_at_houston.rr.NOSPAM.com
>
>
Received on Mon Oct 14 2002 - 07:27:32 CDT