Database Platform or Location Migration

The following Oracle features are available to perform platform migrations:

■ Transportable Database

■ Oracle Streams

■ Oracle Data Pump

■ Transportable Tablespaces

■ Data Guard Redo Apply (Physical Standby Database)

The method you choose to perform these database maintenance tasks depends on the following considerations:

■ Downtime required to complete the maintenance operations

■ Setup time and effort required prior to the downtime

■ Amount of temporary additional resources necessary, such as disk space or CPU

■ Complexity of the steps needed to complete maintenance operations

The following table summarizes the methods that can be used for platform migrations and database upgrades, and recommends which method to use for each operation.

See Also: Oracle Streams Concepts and Administration for more information on database upgrading using Oracle Streams

See Also: Oracle Database Administrator's Guide for more information on transportable tablespaces

4.4.4.1 Transportable Database

Transportable Database is a new feature in Oracle Database 10g Release 2 (10.2) that is the recommended method for migrating an entire database to another platform that has the same endian format.

Note the following points when deciding if Transportable Database is the appropriate method to use when moving a database to another platform:

■ Transportable Database supports moving databases between platforms that are of the same endian format

■ Downtime required for a platform migration when using Transportable Database is determined by the time needed to:

– Place the source database in read-only mode – Convert all data files to the new platform format

– Transfer all data files from the source system to the target system

You can significantly reduce this time by using a storage infrastructure that can make the data files available to the target system without the need to physically move the files.

Transportable Databases is the recommended method for migrating an entire database to another platform that has the same endian format because it’s the simplest

approach.

4.4.4.2 Oracle Streams

Oracle Streams can be used to move a database from one platform to another with minimal downtime. This is because Oracle Streams supports a configuration in which the primary database and its replica are running on different platforms.

Table 4–22 Platform and Location Migration Options

Operation Method When to Use

Platform migration to same endian platform

Transportable Database Recommended method

Oracle Streams Transportable Database will not finish within the maintenance window Platform migration

to different endian platform

Oracle Data Pump Recommended method

Oracle Streams Data Pump will not finish within the maintenance window

Transportable Tablespaces

Database is using data types unsupported by Oracle Streams Location Migration Data Guard Redo Apply

(Physical Standby Database)

Recommended method

Note: Query the V$TRANSPORTABLE_PLATFORM view to determine the endian format of all platforms. Query the V$DATABASE view to determine the platform ID and platform name of the current system.

See Also: Oracle Database Backup and Recovery Advanced User's Guide for more information on cross-platform use of Transportable Database

Note the following points when deciding if Oracle Streams is an appropriate method for a platform migration:

■ Oracle Streams does not support user-defined types, such as object types, REF values, varrays, and nested tables.

■ To perform an upgrade using Oracle Streams, the source database must be running Oracle9i release 2 or higher.

■ The administrative effort required to set up and maintain the Oracle Streams environment is more than if using Data Guard SQL Apply for a database upgrade.

■ There might be a performance impact on the source database while the source and target databases run in parallel as changes are propagated to the target database.

■ Downtime required for a platform migration when using Oracle Streams is determined by the time needed to apply the remaining transactions in the queue and to reconnect clients to the new database.

Consider using Oracle Streams when the application does not use user-defined types and the extra administrative effort is worth the opportunity for a very small outage time.

4.4.4.3 Oracle Data Pump

Oracle Data Pump technology enables very high-speed movement of data and metadata from one database to another, across different platforms and different database versions.

Note the following points when deciding if Data Pump is an appropriate method for a platform migration:

■ Oracle Data Pump is available only on Oracle Database 10g Release 1 (10.1) and later releases.

■ Downtime required for a platform migration when using Data Pump is determined by the time needed to perform a full database network import. A network import uses a database link between the target system and the remote source system to retrieve data and write it directly into the target system, without the use of dump files.

Use Data Pump when moving a database to a platform with different endian format when the network import time is acceptable.

4.4.4.4 Transportable Tablespaces

Transportable tablespaces can be used to accomplish a platform migration by transporting all user datafiles into a pre-created, prepared target database.

Note the following points when deciding if transportable tablespaces is the appropriate method for performing a platform migration:

See Also: Oracle Streams Concepts and Administration for more information on database upgrading using Oracle Streams

See Also:

■ Oracle Database Utilities for more information about Oracle Data Pump and the Export and Import utilities

■ Oracle Database Upgrade Guide for more information about upgrading your Oracle Database software

■ The SYSTEM tablespace cannot be moved with transportable tablespaces. the target database SYSTEM tablespace contents, including user definitions and objects necessary for the clients, must be built manually. Use Data Pump to move the necessary contents of the SYSTEM tablespace.

■ Downtime required for a platform migration or database upgrade when using transportable tablespaces is determined by the time needed to:

– Place the source database tablespaces in read-only mode – Perform a network import of the transportable metadata

– Transfer all datafiles from the source system to the target system

This time can be reduced significantly by using a storage infrastructure that can make the datafiles available to the target system without the need to physically move the files

– Convert all datafiles to the new platform format using RMAN

Use transportable tablespaces to migrate to a new platform when Oracle Data Pump will not complete within the maintenance window, and Oracle Streams or Data Guard SQL Apply cannot be used due to data type restrictions.

4.4.4.5 Data Guard Redo Apply (Physical Standby Database)

Data Guard Redo Apply can be used to change the location of a database to a remote site with minimal downtime by setting up a temporary standby database at a remote location and performing a switchover operation.

Downtime required for a location migration when using Data Guard Redo Apply is determined by the time required to perform a switchover operation.