Oracle Enterprise Manager Conclusion
You should now have a good understanding of the new features within Oracle.
This module discussed
- the backup and recovery scripts within RMAN, which will help you manage the database better;
- the new features within export/import;
- the workings of OEM; and
- the way standby and read-only databases work.
Now that you have completed this module, you should be able to:
- Identify the new features within RMAN
- Explain Fast-Start Fault Recovery
- Explain the new concepts within stand-by database
- Describe the improvements within export/import utilities
- Explore the features of OEM
RMAN changes from Oracle 11g to Oracle 13c
The Oracle Recovery Manager (RMAN), a comprehensive utility for managing the backup and recovery operations of an Oracle database, has undergone significant enhancements from Oracle Database 11g to Oracle Database 13c. These changes include several feature additions and performance improvements that increase RMAN's efficiency, flexibility, and ease of use.
Here are the key modifications introduced to RMAN from Oracle Database 11g to Oracle Database 13c:
- Table Level Recovery: Introduced in Oracle 12c and improved in 13c, RMAN now enables administrators to recover tables or table partitions directly from backups. This feature is highly useful in scenarios where certain tables are accidentally dropped or corrupted.
- Cross-Platform Backup and Recovery: With Oracle Database 12c, RMAN introduced the ability to perform cross-platform backups and recovery, allowing administrators to move a database from one platform to another.
- Multitenant Database Support: Oracle 12c introduced the multitenant architecture, where you can have a container database (CDB) and multiple pluggable databases (PDBs). RMAN was enhanced to support backup and recovery operations at both the CDB level and the individual PDB level.
- Active Database Duplication Enhancements: Oracle 12c made substantial improvements in active database duplication. With these enhancements, you can now duplicate a database without a backup, just by having direct network access to the source data files.
- Backup of Standby Databases: From Oracle 12c onwards, RMAN allows administrators to create image copies of physical standby databases. Also, RMAN can restore and recover a standby control file from a backup control file of the primary database.
- Recovery Manager Command Line Improvements: RMAN's command line interface got significant improvements in Oracle 12c and 13c. For example, commands like "LIST", "REPORT", and "SHOW" were enhanced to provide more details about the RMAN configuration, backup sets, and copy details.
- Support for Container Databases (CDBs): Oracle 13c brought additional enhancements to RMAN's support for container databases. It added the ability to back up and restore individual PDBs within a CDB, giving administrators a more granular control over backup and recovery operations.
- Online PDB Clone: In Oracle 13c, RMAN allows administrators to clone PDBs directly from the source CDB while it is in use. This means you don't have to put the database into read-only mode, which was a limitation in earlier versions.
- Parallel Execution of Backups and Restores: RMAN in Oracle 13c can parallelize backup and restore operations more effectively, leading to significant performance improvements.
These enhancements significantly improve RMAN's capabilities and performance, offering more flexibility and control to DBAs over their backup and recovery operations. However, the DBAs should remember that, as always, they must adapt their backup and recovery strategies to suit the specific needs and architecture of their Oracle Database environment.
RMAN Interaction with a Media Manager
Before performing backup or restore to a media manager, you must allocate one or more channels to handle the communication with the media manager. You can also configure default channels for use with the media manager, which will be applied for all backup and recovery tasks that use the media manager where you do not explicitly allocate channels. RMAN does not issue specific commands to load, label, or unload tapes. When backing up, RMAN gives the media manager a stream of bytes and associates a unique name with this stream. When RMAN needs to restore the backup, it asks the media manager to retrieve the byte stream. All details of how and where that stream is stored are handled entirely by the media manager. For example, the media manager labels and keeps track of the tape and names of files on each tape, and automatically loads and unloads tapes, or signals an operator to do so.
Some media managers support proxy copy functionality, in which they handle the entire data movement between datafiles and the backup devices. Such products may use technologies such as high-speed connections between storage and media subsystems to reduce load on the primary database server. RMAN provides a list of files requiring backup or restore to the media manager, which in turn makes all decisions regarding how and when to move the data.
In this module, you were introduced to the following term file affinity.
File affinity is when the export file created has the role and responsibility of the user within it and when the file is imported by another user,
this user must have the same set of roles and responsibility to complete an import.
In the next module, we will explore the new features and enhancements of Recovery Manager.