DataGuard Question

[lesstjm]

We are implementing DataGuard on our Oracle 10.2.0.5 Solaris environment and I have a question.

We are creating a physical standby in MAXIMUM AVAILABILITY mode. We have redo log shipping between the two. The redo ships between the standby redo log groups between the primary and standby.

The documentation says that the standby redo is applid to the standby and then archived.

So do we have two sets of archive logs? One for the standby database it self and another set of archive logs produced from these standby redo logs?

[vnktummala]

No, only one set. After the standby redo log redo is applied to standby database it will be archived. Standby database redo log files are not archived.

Regards,

[lesstjm]

Thanks for your reply, but I just need to clarify that answer a little more.

So am I correct in saying, the standby redo log gets applied to the standby database. This creates redo on that database and that eventualy creates an archive log. The data in the standby redo log just gets overwritten the next time around.

Is that correct?

[vnktummala]

"Standby redo logs" get applied to standby database and also archived by archiver process when log switch occurs. "Standby database redo logs" never archived.

Excerpt from metalink note 219344.1. Please read the note for more information about how standby redo log works and limitations.

If you have Standby Redo Logs, the RFS process will write into the Standby Redo Log as mentioned above and when a log switch occurs, the Archiver Process of the Standby Database will archive this Standby Redo Log to an Archived Redo Log, while the MRP process applies the information to the Standby Database.

Regards,

[lesstjm]

So you are saying the Standby redo logs get applied and then archived and in the next sentence you say that Standby never gets archived.

which on is it? Do they get archived or do they not get archived???

[vnktummala]

you are confusing with "standby redo logs" and "standby database online redo log files".

do select * from v$logfile in your standby database. You will see all your redo groups with status "ONLINE" and "STANDBY". Groups with ONLINE are standby database online redo log files and they never archive in standby database. Groups with STANDBY are standby redo logs which will be applied to standby database and get archived.

Hope this is clear.

Regards,

[lesstjm]

I got it now. Thanks for yor help.

[vnktummala]

Gald to hear that, your'e most welcome!!!

Regards,