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Archive for May, 2014|Monthly archive page

Cross-Platform Transportable Database and Oracle Engineered Systems

In Consolidation, DBA, Exadata, Oracle database, RMAN, SuperCluster on May 25, 2014 at 15:25

Cross-platform transportable database is not the same thing as transportable tablespace. When performing x-platform transportable database we copy the entire database, including the SYSTEM and SYSAUX tablespaces from one platform to another. The usual containment checks are no longer needed and because the SYSTEM tablespace is also being copied, no metadata datapump export/import step is required. But cross-platform transportable database can only be performed between platforms that have the same endian format.

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When consolidating a large number of databases onto Exadata or SuperCluster, the work has to be automated as much as possible. When the source and the target platform share the same endian (see the 2 endian group below), then the best option is to use the transportable database method.

Otherwise, there are 3 options:

1. Create a new database on the EXA platform manually, and transport the needed tablespaces from the source database using the Cross Platform Transportable Tablespace method.
2. If downtime during the upgrade is an issue, Cross Platform Incremental Backup is an extremely good option. You can Refresh Standby Databases using the method.
3. Use the new Full Transportable Export/Import method. Note that full transportable export is available starting 11.2.0.3 while full transportable import is available starting 12.1.0.1.

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DBAs should consider the following points before the migrations:

– Some parts of the database cannot be transported directly: redo log files and control files from the source database are not transported. New control files and redo log files are created for the new database during the transport process (alter database backup controlfile to trace resetlogs;), and an OPEN RESETLOGS is performed once the new database is created.

– BFILEs are not transported. RMAN provides a list of objects using the BFILE datatype in the output for the CONVERT DATABASE command, but users must copy the BFILEs themselves and fix their locations on the destination database. Execute DBMS_TDB.CHECK_EXTERNAL in order to identify any external tables, directories or BFILEs.

– Tempfiles belonging to locally managed temporary tablespaces are not transported. The temporary tablespace will be re-created on the target platform when the transport script is run. After opening with resetlogs, run alter tablespace TEMP add tempfile…

– External tables and directories are not transported. RMAN provides a list of affected objects as part of the output of the CONVERT DATABASE command, but users must redefine these on the destination platform. Run select DIRECTORY_NAME, DIRECTORY_PATH from DBA_DIRECTORIES and ensure that the same paths are available on the target system.

– Password files are not transported. If a password file was used with the source database, the output of CONVERT DATABASE includes a list of all usernames and their associated privileges. Create a new password file on the destination database using this information.

– When all is done, run UTLIRP and UTLRP.

For SAP users, check Note 105047 – Support for Oracle functions in the SAP environment:

86. Transportable Tablespaces: the implicit use is supported in the BRSPACE function “-f dbcreate” (Note748434) and the “Tablespace Point in Time Recovery” function of BRRECOVER. Explicit use as part of system copying is tolerated.

87. Transportable database: Can be used (Note 1367451).

And finally, here is some more information on how to migrate your databases to Oracle Engineered Systems:

1. Exadata MAA Best Practices Series Session 6: Migrating to Exadata

2. Exadata MAA Best Practices Migrating Oracle Databases

3. Oracle’s SPARC M5-32 and SPARC M6-32 Servers: Domaining Best Practices

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