|Postprocessing And Remarks|
- If not yet done, now is the time to apply the parameter adjustments to
the master database, as mentioned in the
- Your new standby database is created, but not yet automatically recovering.
So you need to issue the
ALTER DATABASE RECOVER MANAGED STANDBY
DATABASE DISCONNECT; command at the sqlplus prompt, logged in as SYSDBA
- Though starting with 10g, Oracle automatically detects a standby database when
STARTUP command is issued, and opens it read only - it again
does not start the managed recovery automatically. So you still need to
take care that this is done after server restart.
- Optionally, you may want to create STANDBY LOGFILE GROUPs (see below).
Concerning the standby logs, let me quote a part of a Metalink documentation here:
"Standby redo logs are
necessary for the higher protection levels such as Guaranteed, Instant, and
Rapid. In these protection modes LGWR from the Primary host writes transactions
directly to the standby redo logs. This enables no data loss solutions and
reduces the amount of data loss in the event of failure. Standby redo logs are
not necessary if you are using the delayed protection mode."
That is, by default we don't need them (since we use the deferred method: Redo
log is applied to the standby after the primary has archived it, which means a
certain delay). If your concern is to have the standby immediately applying redo
information as soon as it is generated on the primary instance, i.e. without any
delay - then
you will need the standby logs. But remember in this case
to configure them on both, the primary and
the standby database - though
they are not used on a primary instance, after a SwitchOver/FailOver
the primary becomes the
standby and should be prepared for this task.
There are some more things to take care of if you are going to configure standby
logs - too much for our little article, so please refer to the Oracle documentation.
Two hints I give you: One is the command,
ALTER DATABASE ADD STANDBY
, so you know what to look for. The other is a Metalink document
on this topic, see note 180031.1
Most of these steps can be automated using the RMAN
wrapper from the
framework. These are:
- Automatic backups using the FRA
- Of course also managing those backups, restoring, recovering...
- Starting with v0.2.2: Guided creation of a standby database
The last mentioned feature will guide you step by step through what was explained
in this article. Many things as creating a backup, creating a copy of the
controlfile, turning on the managed recovery, will be done automatically when
you answered the corresponding question with yes. However, some steps must still
be done manually, as editing the configuration files, and copy files to the
On the standby database, we cannot use Oracles DB
Console (since this one always
places its repository in the local database itself, which is read only in case
of a standby database and thus cannot be used; there is no way to place the
repository in a different database). So if you want an interface like that for
administration, you will need to setup Grid Control. But this is a topic for
- MetaLink Note 789370.1: Creating physical standby using RMAN duplicate without shutting down the primary