Implementing Data Guard - Expert Consolidation in Oracle Database 12c - page 346

DGMGRL> add database "CDB1DCB"
> as connect identifier is "CDB1DCB"
> maintained as physical;
Database "CDB1DCB" added
DGMGRL> add database "CDB1DCC"
> as connect identifier is "CDB1DCC"
> maintained as physical;
Database "CDB1DCC" added
DGMGRL>

The Broker has been told to add two databases to the configuration as physical standby databases. If you had a
logical standby database you could use the “maintained as logical” clause instead. Now review the configuration you
just created:

DGMGRL> show configuration;

Configuration - apress

Protection Mode: MaxPerformance
Databases:
CDB1DCA - Primary database
CDB1DCB - Physical standby database
CDB1DCC - Physical standby database

Fast-Start Failover: DISABLED

Configuration Status:
DISABLED

As you can see Oracle has correctly added our two standby databases into the configuration. Thankfully the
configuration is not enabled by default, there is some more work to be done. Every database in the configuration can
be queried and managed using the Broker interface. The databases have certain properties which are settable, some
are read-only. Using the broker interface you control these; think of the Broker as another way of executing alter
system statements.

■ Do not try and modify Data guard related parameters in the initialization files! You would only confuse the
Broker. If you did anyway, you had to do a manual reconciliation of the Broker and database parameters.

Caution

Other parameters have a different scope and belong to the configuration as such. The best example for one of
these is the protection mode.
To complete the Broker configuration, the following tasks need to be executed:

• Statically register the broker services with the listener

• Automate the management of standby database files

• Optionally define a delay for the application of redo to the standby database CDB1DCC. This

is truly optional but allows you to have a safety net for human error. Detected quickly enough
the trailing standby database can be activated in case of a catastrophic logical corruption

• Change the protection mode to maximum availability