DGMGRL Command Tips Oracle Database Tips by Donald BurlesonDecember 9, 2015

Oracle Data Guard - Data Guard Broker

Managing Data Guard Using DGMGRL

Data Guard manager greatly simplifies the otherwise complicated tasks of log management, role management, and data protection modes. It can be used to monitor the overall health of the entire configuration as well as an individual site. This section will investigate the use of the CLI interface of Data Guard manager to administer a configuration.

The information presented will start with the creation of a configuration followed by more complicated tasks such as log management, switchover, failover and manipulating data protection modes. As always, Oracle documentation remains the largest single source of information on this topic.

Data Guard Configuration Management

As explained earlier, a configuration contains the primary and standby sites. In this section, the pre-requisites and procedures to create a configuration will be presented.

One requirement of creating a configuration using the CLI interface is that the standby databases participating in the configuration should exist. CLI interface cannot be used to create a standby database.

Assume that the primary database "appsdb", physical Oracle instance "stdbydb" and logical Oracle instance "logstdby" already exist. To create a configuration, ensure that the broker is running on the primary and all participating standby databases. On the primary site, start the CLI environment and connect to the primary database.

DGMGRL>connect sys/<sys password>

An account with the SYSDBA privilege will have to be used.

Use the CREATE CONFIGURATION command to create a configuration. The following code snippet shows the usage of this statement in Oracle9i:

CREATE CONFIGURATION 'appsconfig' AS PRIMARY SITE IS 'appsdb'
RESOURCE IS 'appsdb' HOSTNAME IS 'jrpr01' INSTANCE NAME IS 'appsdb'
SERVICE NAME IS 'appsprimary' SITE IS MAINTAINED AS PHYSICAL;

Oracle will validate the HOSTNAME and INSTANCE NAME from the v$instance view. Arguments Configuration, Site and Resource are user–defined labels. The service name should match the SQL*Net service name for the primary database on all hosts participating in the configuration. There should be an identical service-naming scheme on all the host machines within a configuration.

The last argument, SITE MAINTAINED AS, signifies the type of Oracle instance that this primary database will assume after the switchover operation. When a primary database is marked as physical, it cannot be turned into a logical Oracle instance by switching it over with a standby database. The CREATE CONFIGURATION statement has been simplified in Oracle10g:

Data Guard Configuration Tips

Data Guard Configuration attributes

Viewing Configuration and Site Attributes

DGMGRL> SHOW RESOURCE VERBOSE 'appsdb' ON SITE 'appsdb';
Resource
  Name:             appsdb
  Manager Type:     internal
   Standby Type:     PHYSICAL
Online States:
  ONLINE
  PHYSICAL-APPLY-READY
  PHYSICAL-APPLY-ON
  READ-ONLY
  LOGICAL-APPLY-READY
  LOGICAL-APPLY-ON
  READ-WRITE
  READ-WRITE-XPTON
Properties:
  INTENDED_STATE                  = 'READ-WRITE-XPTON'
  ENABLED                         = 'yes'
  IGNORE_STATUS                   = 'no'
  LogXptMode                      = 'ARCH'
  Dependency                      = ''
  Alternate                       = ''
  DelayMins                       = '0'