Re: Data Guard Physical standby 9i archive log registration

  • From: "goran bogdanovic" <goran00@xxxxxxxxx>
  • To: ag@xxxxxxxxxxxx, ranko.mosic@xxxxxxxxx
  • Date: Mon, 12 Nov 2007 10:48:35 +0100

you do not need to 'register' them if you use 'automatic' option to recover
db (if DG is properly configured). From manual:
"The AUTOMATIC option automatically generates the name of the next archived
redo log file needed to continue the recovery operation."

you may or may not register them if you are interested in just failover or
switchover...if you do a switchover or failover and your physical standby
become primary, new primary should have information of all your archive log
files after and before role change in first place considering your
backup/recovery strategy. What is you backup strategy now?
On the other hands it also depends on your need. Imagine for some 'strange'
reason you need to do a tablespace point-in-time recovery and the time to
recover is before a role change and your new primary does not have
information about all archivelog files as of recovery time...or you decide
to do a backup on can always do the workaround to restore them
from tape, manually register etc...but the question is do you really need
this overhead and have time for this in urgent situation?

You may also have your standby all the time in recovery mode and just
transfer log files to standby server, register them and MRP will then pick
it up and recover db automatically. You have then one step less and have
also all your logfiles registered...


On Nov 12, 2007 3:50 AM, Alex Gorbachev <ag@xxxxxxxxxxxx> wrote:

> Ranco,
> I haven't seen any replies so here it goes...
> I think you can't register dummy redo logs - I remember that I had
> issues registering corrupted archivelogs on standby.
> As far as I understand, you need to register them to make available
> managed log apply process. Otherwise, it won't find them.
> This mean that after they have been applied with manual recovery, they
> don't need to be registered.
> In fact, you don't really want them registered if they are deleted and
> if you do want them registered, you should run crosscheck archivelog
> from RMAN so that it at least mars them unavailable.
> I might have missed something here so if someone noticed something
> strange - please correct.
> Cheers,
> Alex
> On Nov 1, 2007 6:25 PM, Ranko Mosic <ranko.mosic@xxxxxxxxx> wrote:
> > Hi List,
> > I am maintaining above mentioned database.
> > We will switch to automactic archive log transfer (
> > log_archive_dest_state_2 = ENABLE ).
> > Until that happens archive logs are transferred using OS command and
> > "recover automatic standby database parallel 44" command runs.
> > Once applied,  logs are ( also manually ) registered.
> > Question:
> > Is archive log registration a must for proper functioning ( if we want
> > failover later, switchover etc ) ?
> > Some logs were deleted before registered ( so they are applied, just
> > not registered ).
> > Do we have to restore those logs from tape, or we could safely skip
> > this step all together ( contrary to what manuals say ) ?
> > Can we just create dummy arch log files and register those ? Does
> > Oracle do any checks on file contents, or this is mere formality and
> > any file with proper name will do ?
> >
> > --
> > Regards,
> > Ranko Mosic
> > Consultant Senior Oracle DBA
> > B. Eng, Oracle 10g, 9i Certified Database Professional
> > Phone: 416-450-2785
> > email: mosicr@xxxxxxxxxx
> >
> > --
> >
> >
> >
> >
> --
> Alex Gorbachev, Oracle DBA Brewer, The Pythian Group
> BAAG party -
> --

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