About Oracle Data Guard
This topic provides an overview of Oracle Data Guard and describes how Oracle Base Database Cloud@Customer integrates with Oracle Data Guard to provide a managed disaster recovery solution. It also introduces the key concepts and service capabilities for deploying and managing Data Guard associations.
Oracle Data Guard provides a comprehensive set of services that create, maintain, manage, and monitor one or more standby databases to enable production Oracle AI Databases to mitigate disasters and data corruption.
Oracle Data Guard maintains standby databases as copies of the production database. If the production database becomes unavailable because of a planned or unplanned outage, Oracle Data Guard can transition a standby database to the production role, minimizing the downtime associated with the outage. Oracle Data Guard can be used with traditional backup, restore, and cluster techniques to provide a high level of data protection and data availability. Oracle Data Guard transport services are also used by other Oracle technologies, such as Oracle Streams and Oracle GoldenGate, for the efficient and reliable transmission of redo data from a source database to one or more remote destinations.
This guide describes how to use Oracle Data Guard with Oracle Base Database Cloud@Customer. It provides an overview of the Oracle Data Guard features supported by the service and explains how to create, manage, and monitor Data Guard associations using the Console and API.
Oracle Data Guard Broker simplifies the creation, management, monitoring, and role transitions of Oracle Data Guard configurations. Oracle Base Database Cloud@Customer automatically configures Oracle Data Guard Broker when you create a Data Guard association.
For detailed information about Oracle Data Guard concepts, architecture, and administration, see Oracle Data Guard Concepts and Administration and Oracle Data Guard Broker Concepts.
Oracle Data Guard in Oracle Base Database Cloud@Customer
Oracle Base Database Cloud@Customer integrates Oracle Data Guard with service-managed operations to simplify the deployment and management of disaster recovery configurations.
A Data Guard association is a managed Oracle Data Guard configuration consisting of a primary database and one or more physical standby databases. The primary and standby databases use identical Oracle AI Database software versions.
When you create a Data Guard association, Oracle Base Database Cloud@Customer provisions the standby database, configures Oracle Data Guard Broker, establishes redo transport and apply services, and synchronizes the standby database with the primary database.
If Oracle Active Data Guard is supported by your deployment, the standby database can also be configured as an open read-only database.
You can use the Console or API to perform the following Data Guard management operations:
- Create and delete Data Guard associations.
- Monitor the health and synchronization status of the Data Guard configuration.
- Perform switchover operations for planned maintenance.
- Perform failover operations during unplanned outages.
- Reinstate the former primary database, when supported.
Oracle Data Guard Architecture
This section describes the key components of an Oracle Data Guard configuration and how they work together to provide high availability and disaster recovery for Oracle AI Database.
An Oracle Data Guard configuration consists of a primary database and one or more standby databases. The primary database processes application transactions and generates redo data. Oracle Data Guard continuously transmits this redo data to the standby database to keep it synchronized with the primary database.
Primary Database
The primary database is the production database that accepts application connections and processes database transactions. Changes made to the primary database generate redo data, which Oracle Data Guard transmits to the standby database.
Physical Standby Database
A physical standby database is a transactionally consistent copy of the primary database. Oracle Data Guard automatically applies redo data received from the primary database to keep the standby database synchronized. If the primary database becomes unavailable, the standby database can assume the primary role through a switchover or failover operation.
If Oracle Active Data Guard is supported by your deployment, the physical standby database can be opened in read-only mode while continuing to apply redo received from the primary database.
Redo Transport and Apply
Oracle Data Guard transports redo data generated on the primary database to the standby database through redo transport services. The standby database continuously applies the received redo to maintain synchronization with the primary database and minimize data loss during planned or unplanned role transitions.
Oracle Data Guard Broker
Oracle Data Guard Broker is the management framework for Oracle Data Guard. It automates the creation, management, monitoring, and role transitions of Data Guard configurations. Oracle Base Database Cloud@Customer automatically configures Oracle Data Guard Broker when you create a Data Guard association.
Data Guard Association
In Oracle Base Database Cloud@Customer, a Data Guard association is the managed OCI resource that represents an Oracle Data Guard configuration. You can use the Console or API to create and manage Data Guard associations, monitor their health, and perform role transition operations.
Role Transition Operations
Oracle Data Guard enables role transitions between the primary and standby databases to support planned maintenance and disaster recovery. Depending on your operational requirements, you can perform a switchover or failover operation. After a failover, you can reinstate the former primary database as a standby database, when supported.
Switchover
A switchover is a planned role transition between the primary and standby databases. During a switchover, the primary database assumes the standby role, and the standby database assumes the primary role without data loss. Switchover operations are typically performed before planned maintenance activities, such as database updates, infrastructure maintenance, or hardware upgrades.
Failover
A failover is an unplanned role transition that promotes a standby database to the primary role when the primary database becomes unavailable because of an outage or failure. Depending on the failure scenario and the configured protection mode, a failover might result in some data loss.
Reinstate
After a successful failover, the former primary database can be reinstated as a standby database instead of being recreated. Reinstating the former primary database restores the Data Guard configuration and allows it to resume synchronization with the new primary database.
Supported Configurations
This section describes the Oracle Data Guard configurations supported by Oracle Base Database Cloud@Customer.
Oracle Base Database Cloud@Customer supports Oracle Data Guard physical standby databases for disaster recovery and high availability. A Data Guard association can consist of a primary database and one or more physical standby databases. The primary and standby databases must use identical Oracle AI Database software versions.
The following Data Guard capabilities are supported by Oracle Base Database Cloud@Customer:
| Capability | Supported Configuration |
|---|---|
| Standby database type | Physical standby |
| Maximum standby databases | TBD |
| Oracle Active Data Guard | Supported/Not supported |
| Oracle Data Guard Broker | Supported |
| Oracle AI Database software version | Primary and standby databases must use identical software versions |
Observe the following requirements when deploying a Data Guard configuration:
- The primary and standby databases must use identical Oracle AI Database software versions.
- The standby database must be created using a compatible database home.
- Oracle Data Guard Broker is automatically configured and managed by the service.
- Oracle Active Data Guard requires the appropriate licensing and is available only if supported by your deployment.
Prerequisites
Review the following prerequisites before creating a Data Guard association in Oracle Base Database Cloud@Customer.
Infrastructure Requirements
Ensure that the primary and standby databases are deployed on supported Data Infrastructure resources. Verify that the infrastructure has sufficient resources to host both the primary and standby databases.
Database Requirements
Before creating a Data Guard association, ensure that:
- The primary database is running a supported Oracle AI Database release.
- The primary and standby databases use identical Oracle AI Database software versions.
- The primary and standby databases use compatible database homes.
- The primary database is in a healthy state.
Network Requirements
Ensure that network connectivity is available between the primary and standby databases. The network must provide sufficient bandwidth and reliability to support continuous redo transport and synchronization.
Security Requirements
Before configuring Oracle Data Guard:
- Oracle Transparent Data Encryption (TDE) must be configured as required by the service.
- Ensure that you have the required IAM permissions to create and manage Data Guard associations.
- Ensure that the required database administrative credentials are available.
Operational Requirements
Before creating a Data Guard association, consider the following:
- Verify that the standby location meets your disaster recovery requirements.
- Review the supported configurations and service limits.
- Ensure that any required Oracle AI Database or Oracle Active Data Guard licenses are available.
Other Requirements and Limitations
Review the following requirements before deploying and managing Oracle Data Guard with Oracle Base Database Cloud@Customer.
Planned and Unplanned Role Transitions
Use a switchover for planned maintenance activities when both the primary and standby databases are available. Use a failover only when the primary database is unavailable because of an unplanned outage.
Data Protection
The level of data protection depends on the configured protection mode and the availability of redo data. Depending on the failure scenario, a failover operation might result in data loss.
Backup and Recovery
Oracle Data Guard complements, but does not replace, your backup and recovery strategy. Continue to perform regular database backups to protect against logical corruption, user errors, and other recovery scenarios that require restoring data from backup.
Monitoring
Regularly monitor the health and synchronization status of your Data Guard configuration to ensure that redo transport and apply services are operating usually. Address warnings or errors promptly to maintain the required level of data protection and availability.
Service Limitations
Oracle Base Database Cloud@Customer supports only the Oracle Data Guard features and configurations documented for the service. Review the supported configurations before creating or modifying a Data Guard association.