Database Reference
In-Depth Information
Configuration - dbaas
Protection Mode: MaxPerformance
Databases:
CDB1 - Primary database
STDB1 - Physical standby database
Fast-Start Failover: DISABLED
Configuration Status:
SUCCESS
It is as simple as that.
Managing and administering Data Guard
As with most Oracle technologies Data Guard can be managed in a number of ways, including command line and graphical
user interface. The command line tools include SQL*Plus as well as dgmgrl , the Data Guard Manager Line Mode.
Managing using SQL*Plus
All Data Guard operations can be managed via SQL*Plus. Although the management of the configuration via
SQL*Plus gives the administrator the greatest flexibility, it requires profound knowledge of the inner workings of Data
Guard. The aim of this topic is to simplify management and also deal with the fact that first- and second-level support
may be outsourced. While it is still desirable for any database administrator to understand how Data Guard works in
detail it should not be assumed that such knowledge is readily available. Depending on your organizational structure,
troubleshooting Data Guard may be left to third-line support.
The remaining sections of this chapter therefore deal with a simplified yet very powerful interface to Data
Guard-the Data Guard Broker.
Management using the Data Guard Broker
The Data Guard Broker is an integral part of the replication framework that lets you define Data Guard configurations,
including support for all types of standby databases. The Broker is installed by default with the RDBMS binaries. Its
architecture was added to Data Guard in Oracle 9 i , and it is a mature but little-used feature. From a user's point of
view, the Data Guard Broker simplifies the setup, maintenance, and monitoring of Data Guard configurations, as
well as role transitions. The Broker fully supports Oracle RAC and RAC One Node as well. The tight integration into
Enterprise Manager also allows the creation of a standby database through simple mouse movements and a few key
strokes. The usability of the Enterprise Manager integrated Broker is higher than the command line interface via
dgmgrl which is alternatively available to the administrator. Enterprise Manager is more feature rich but requires
additional infrastructure, which your organization may already have in place anyway.
When used, Data Guard Broker will rely on its own binary configuration files and additional background
processes to configure the relevant initialization parameters upon instance start; it will also monitor the databases
in the configuration. In clustered environments the configuration files need to be on shared storage. ASM, raw
devices, and cluster file systems are possible candidates to store the files; ASM really is the best choice. You do not
have to replicate the configuration on each database. Rather, the broker will automatically preserve the single image
view of your Data Guard configuration by replicating changes to all databases involved. You should not try to issue
SQL commands through sqlplus to modify the Data Guard configuration because your changes are likely to be
overwritten the next time the Data Guard broker starts: once the broker, always the broker; unless you remove or
disable the Broker configuration.
 
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