Standby Database Configuration Options

When adding a standby database, you can specify the following details:

• Peer VM Cluster Details: If the target is ExaDB-D, you can select the Exadata Infrastructure.
• Target Service Selection: Choose either ExaDB-D or ExaDB-XS. By default, the service initiating the Data Guard group is selected.. If a service is unavailable in the selected region, it is disabled with the message: 'Service is not available in this region".
• Data Guard Type: The group can be configured with either Data Guard or Active Data Guard, and each standby database can have a different type.
• Data Guard Group Limitation: A primary database is limited to one Data Guard group.
• Standby Database Creation: Only one standby database can be added at a time. However, standby databases can be created in any of the following categories without restrictions on their number:
  • Within the same service
  • Across services
  • Within the same Availability Domain (AD)
  • Across Availability Domains within the same region
  • Across regions

Key Considerations for cross-service primary and standby databases

• Both the primary and standby databases must use the same key management solution.
• Data Guard can be configured in Max Performance or Max Availability protection mode with Sync or Async transport type, subject to the following rules:
  • For the first standby database:
    • Defaults to Max Performance mode with Async transport.
    • Protection mode and transport type cannot be changed.
  • For the second and subsequent standby databases:
    • Inherits the protection mode from the first standby.
    • Defaults to Async transport.
    • Protection mode and transport type cannot be changed.

Viewing and Editing Data Guard Configuration

• View all databases that are part of the Data Guard group in the Data Guard Group table, irrespective of whether you are on the primary or standby database pages.
• Edit the Data Guard configuration to update:
  • Data Guard type: Can be different for each standby database. This can be changed only from a standby database.
  • Database administrator password: Can be edited from any database.
  • Protection mode: Can be switched between Max Performance and Max Availability from the primary or any standby database.
  • Transport type: Can be switched between Async and Sync only from a standby database.

To achieve zero data loss, you require at least one standby with Sync transport. It is recommended to have a standby with Sync transport in the same service as the primary database.

Switchover and Failover

• Switchover (on any standby database)
  • Switchover is performed without enforcing a major version or Release Update (RU) check. However, a warning appears if the standby database has asymmetric configuration, such as differing node counts, memory, or service type.
• Failover (on any standby database)
  • Failover is performed without enforcing a major version or Release Update (RU) check. However, a warning appears if the standby database has an asymmetric configuration, such as differing node counts, memory, or service type.

Backup and Restore

• Scheduled and Automatic Backups
  • You can schedule automatic backups on the primary database, standby database, or both.
  • Both Object Storage and Recovery Service backups are supported.
  • If backups are configured on both primary and standby databases, they must use the same backup destination type.
• In-Place Restore of the Same Database within ExaDB-XS

  Restore and recover a database using a backup taken from the same database in ExaDB-XS:

  • Restore primary using a backup taken on the primary database.
  • Restore standby using a backup taken on the standby database
• In-Place Restore of a Peer Database within ExaDB-XS
  Restore and recover a peer database (which has no backups configured) using a backup from the source database with Recovery Service:

  • Scenario 1: Restore the primary using the standby backup.
    • Primary database: ExaDB-XS (no backups configured)
    • Standby database: ExaDB-XS (backups configured to Recovery Service)
  • Scenario 2: Restore the standby using the primary backup.
    • Primary database: ExaDB-XS (backups configured to Recovery Service)
    • Standby database: ExaDB-XS (no backups configured)
• In-Place Restore of a Peer Database Across Services

  Restore and recover a database in ExaDB-XS or ExaDB-D using a backup from the source database in the opposite service (ExaDB-D or ExaDB-XS) with Recovery Service:

  • Scenario 1: Restore a peer database in ExaDB-XS using a backup from ExaDB-D
    • Use Case 1: Restore primary using the standby backup.
    • Use Case 2: Restore standby using the primary backup.
  • Scenario 2: Restore a peer database in ExaDB-D using a backup from ExaDB-XS
    • Use Case 1: Restore primary using the standby backup.
    • Use Case 2: Restore standby using the primary backup.

Out-of-Place Restore (Creating a New Database)

• Within ExaDB-XSYou can create a new database in ExaDB-XS using a backup from the same service.
  • Restore within:
    • The same Availability Domain (AD)
    • A different AD within the same region
    • A different region
  • Supports Object Storage or Recovery Service as the backup destination..
• Across Services
  • Scenario 1: Create a New Database in ExaDB-D Using a Backup from ExaDB-XS
    • Source: ExaDB-XS (database and backups)
    • Target: ExaDB-D (any region or AD)
    • Backup Destination: Object Storage or Recovery Service
  • Scenario 2: Create a New Database in ExaDB-XS Using a Backup from ExaDB-D
    • Source: ExaDB-D (database and backups)
    • Target: ExaDB-XS (any region or AD)
    • Backup Destination: Object Storage or Recovery Service