1. Administering Oracle Database Exadata Cloud Service (OCI-C)
  2. Migrating Oracle Databases to Exadata Cloud Service
  3. Migration Methods
  4. Data Guard Physical Standby

Data Guard Physical Standby

An Oracle Data Guard physical standby database is a block-for-block replica of a primary database. You can use Data Guard to replicate your source database to Exadata Cloud Service. Afterward, you can decouple the databases and use the physical standby as your new master. You can use this method in conjunction with source databases from a selection of little-endian platforms.

Oracle Data Guard provides a comprehensive set of features that create, maintain, manage, and monitor standby databases. Data Guard is primarily used to maintain standby databases for the purposes of disaster recovery. During normal operations, the standby database is constantly updated with changes from the primary database. If the primary database fails for any reason, the standby database can be used to support the application workload.

Oracle Data Guard can also be used to facilitate data migration. You can start by creating a standby database in the target environment. After the standby is created and brought up to date with the primary database, you can perform a switchover and make the standby the new primary database. Finally, you can decouple the databases and continue using the original standby as your migrated database.

To host a Data Guard physical standby database on Exadata Cloud Service, your source database must reside on Linux x86–64 (the same as Exadata Cloud Service) or a compatible little-endian platform. Compatible platforms include Linux x86, Windows x86 (32–bit or 64–bit) and Solaris x86. See What differences are allowed between a Primary Database and a Data Guard Physical Standby Database for details about Data Guard support for different platforms. Also, the primary and standby databases must have the same compatibility setting, which means that your source database must be upgraded to a version of Oracle Database supported by Exadata Cloud Service before Data Guard is configured.

When you instantiate the Data Guard physical standby database, you use a block-for-block copy of the primary database, and the standby database automatically uses the database character set of the primary database. You should carefully consider whether the physical organization and character set of your source database is suitable for use in conjunction with Exadata Cloud Service before selecting this approach.

To perform a database migration using a Data Guard physical standby database, you perform these tasks:

  1. Create a database deployment on Exadata Cloud Service that will eventually incorporate your migrated database.

  2. Manually delete the Exadata Cloud Service database that is created in conjunction with the database deployment in step 1.

  3. Create the standby database on Exadata Cloud Service using the database deployment created in step 1. This will be the migrated database.

  4. Configure Transparent Data Encryption (TDE).

  5. Configure automatic backups for the migrated database.

  6. Perform a Data Guard switchover, so that the migrated database assumes the primary database role in the Data Guard configuration.

  7. Register the migrated database with the Exadata Cloud Service tooling and Web console.

  8. Decouple the databases by stopping the Data Guard redo apply services and removing the initialization parameter settings for Data Guard. At this point, you can decommission your original source database.

For detailed instructions, see Migration to Exadata Cloud using Simple Data Guard Approach with Minimal Downtime.

See also Creating a Physical Standby Database in Oracle Data Guard Concepts and Administration for Release 18, 12.2, 12.1, or 11.2.