There are two types of database properties: monitorable and configurable. Both monitorable and configurable properties can be further divided into those properties that have database scope and those having instance scope.
■ Monitorable property values can be viewed only when the associated database object is enabled.
Monitorable properties allow you to view run-time information related to database objects, but you cannot change the values of these properties. ■ Configurable property values can be viewed and dynamically updated.
Configurable properties affect the operation or configuration of the broker. You can change the value of these properties using DGMGRL or Enterprise Manager. You can edit properties if the configuration and its databases are enabled or disabled. However, if the database is disabled, the new property value will not take effect until you enable the configuration or database, as appropriate.
To see these properties, you can use the DGMGRL SHOW command or Edit Properties page in Enterprise Manager. Example 4–1 uses the SHOW DATABASE VERBOSE command to display information about the North_Sales database.
Example 4–1 Using the SHOW DATABASE VERBOSE Command to Display Properties
DGMGRL> SHOW DATABASE VERBOSE North_Sales;
Database
Name: North_Sales Role: PRIMARY
See Also: Section 4.5 on page 4-11 for more details on managing Redo Apply
See Also:
■ Section 4.5 on page 4-11 for information about managing SQL Apply
■ Oracle Data Guard Concepts and Administration for information about the database guard
Database Properties
Enabled: NO
Intended State: TRANSPORT-ON Instance(s): sales1 Properties: DGConnectIdentifier = 'North_Sales.foo.com' ObserverConnectIdentifier = '' LogXptMode = 'ASYNC' DelayMins = '0' Binding = 'OPTIONAL' MaxFailure = '0' MaxConnections = '1' ReopenSecs = '300' NetTimeout = '30' RedoCompression = 'DISABLE' LogShipping = 'ON' PreferredApplyInstance = '' ApplyInstanceTimeout = '0' ApplyParallel = 'AUTO' StandbyFileManagement = 'AUTO' ArchiveLagTarget = '0' LogArchiveMaxProcesses = '5' LogArchiveMinSucceedDest = '1' DbFileNameConvert = 'dbs/bt, dbs/t' LogFileNameConvert = 'dbs/bt, dbs/t' FastStartFailoverTarget = '' StatusReport = '(monitor)' InconsistentProperties = '(monitor)' InconsistentLogXptProps = '(monitor)' SendQEntries = '(monitor)' LogXptStatus = '(monitor)' RecvQEntries = '(monitor)' HostName = 'stacm29' SidName = 'b2' StandbyArchiveLocation = '/archfs/arch/' AlternateLocation = '' LogArchiveTrace = '8191' LogArchiveFormat = 'db1r_%d_%t_%s_%r.arc' LatestLog = '(monitor)' TopWaitEvents = '(monitor)'
Current status for "North_Sales": DISABLED
4.3.1 Monitorable (Read-Only) Properties
Monitorable database properties allow you to view information related to the database, but you cannot change the values of these properties. These properties can be very helpful when you are trying to diagnose problems in the broker configuration. For example, you can view the InconsistentLogXptProps monitorable database property to determine where there is a discrepancy in redo transport services properties between the broker configuration file and the actual value currently used by the database.
You can list all monitorable database properties using the DGMGRL SHOW DATABASE VERBOSE command. Use the SHOW DATABASE command to obtain more details about
See Also: Chapter 8 for complete information about the DGMGRL command-line interface
Database Properties
a particular property. For example, the following shows the InconsistentLogXptProps property:
DGMGRL> SHOW DATABASE 'North_Sales' 'InconsistentLogXptProps'; INCONSISTENT LOG TRANSPORT PROPERTIES
INSTANCE_NAME STANDBY_NAME PROPERTY_NAME MEMORY_VALUE BROKER_VALUE sales1 DR_Sales DelayMins 30 10
Enterprise Manager displays the information obtained from these properties on the Edit Properties page.
4.3.2 Configurable (Changeable) Database Properties
Configurable database properties affect the operation or configuration of the database. When you use DGMGRL or Enterprise Manager to create a primary database object and import existing standby databases into a new broker configuration, the property values are initially imported from the database settings.
You can update many property values when the database is either disabled or
enabled. When a new database is added into the configuration, the broker connects to the database and imports initial values for the database properties from the current database settings. For example:
DGMGRL> SHOW DATABASE 'North_Sales' 'ArchiveLagTarget'; ArchiveLagTarget = '0'
DGMGRL> EDIT DATABASE 'North_Sales' SET PROPERTY 'ArchiveLagTarget'=1200; Property "ArchiveLagTarget" updated
DGMGRL> SHOW DATABASE 'North_Sales' 'ArchiveLagTarget'; ArchiveLagTarget = '1200'
When the configuration is enabled, the broker keeps the database property values in the broker configuration file consistent with the values being used in the database. For those that are related to initialization parameter properties, the broker maintains the consistency among the value in the broker configuration file, the current database value, and the initialization parameter value in the server parameter file, as follows: ■ For dynamic parameters, the broker keeps the value of the database parameter
consistent in the system global area (SGA) for the instance, in the broker configuration file, and in the server parameter file.
■ For static parameters and properties, the database parameter value in the system global area (SGA) for the instances may temporarily differ from what is in the broker configuration file and in the server parameter file. Typically, the database value becomes the same as the server parameter file value and the broker configuration file value the next time the database instance is stopped and restarted.
Even when the configuration is disabled, you can update database property values through the broker. The broker retains the property settings (without validating the values) and updates the database initialization parameters in the server parameter file and the settings in memory the next time you enable the broker configuration.
Managing Redo Transport Services