2. Oracle Recovery Manager (RMAN) 10g : Reloaded
Boris Gurov
Support Engineer
Oracle Bulgaria

3. Agenda What is Recovery Manager? Automatic disk based recovery
Optimized incremental backups
Incrementally updated backups
Just say no to shrinking backup windows
A new twist to transportable tablespaces
Q&A

4. Recovery Manager: Oracle’s Backup & Recovery Utility
Over 25 Man Years of Engineering Technology provides:
Intimate knowledge of database file formats and recovery procedures
Manages and automates the backup, restore, and recovery process
Creates and maintains backup policies
Catalogs all backup and recovery activities
Operates on-line and in parallel for fast processing
Corrupt block detection during backup and restore and the ability to validate backups
Integrated with Enterprise Manager & 3rd party network backup products
Recovery
Manager
Enterprise Manager
& 3rd Party Tools
Media Management Layer
Network

5. New World: Disk Based Data Recovery
Disk economics are close to tape
Disk is better than tape
Random access to any data
We rearchitected our recovery strategy to take advantage of these economics
Random access allows us to backup and recover just the changes to the database
Backup and Recovery goes from hours to minutes
1980’s MB
1000x increase
Traditional Recovery was designed 15 years ago
Log files capture all changes
Backup database & logs to tape nightly
Recover by restoring backups and applying logs
Traditional recovery is slow
Restore time depends on DB size
Roll forward time depends on time since last backup
Times measured in hours
2000’s GB

6. Flash Recovery Area
Unified storage location for all recovery files and recovery related activities in an Oracle Database.
Centralized location for control files, online redo logs, archive logs, flashback logs, backups
A flash recovery area can be defined as a directory, file system, or ASM disk group
A single recovery area can be shared by more than one database
Minimize the number of initialization parameters to set when you create a database
Define a database area and flash recovery area location
Oracle creates and manages all files using OMF
The flash recovery area is a unified storage location for all recovery related files
and activities in an Oracle database. All files that are needed to completely recover
a database from a media failure are part of the flash recovery area. The recovery
related files include:
Control file: A copy is created in the flash recovery area location at database
creation.
Archived log files: When the flash recovery area is configured,
LOG_ARCHIVE_DEST_10 is automatically set to the flash recovery area
location. The Archiver background process then creates archived files in the flash
recovery area and in other configured LOG_ARCHIVE_DEST_n locations. If no
LOG_ARCHIVE_DEST_n locations are defined, then the default for archived files
is in the flash recovery area.
Flashback logs: Flashback must be enabled to generate flashback logs.
Control file autobackups: The default location for control file autobackups
created by RMAN and autobackups generated by the Oracle database server is the
flash recovery area.
Data file copies: The BACKUP AS COPY command creates data file copies in
the flash recovery area.
RMAN files: The default location for RMAN to create files during backup, copy,
tablespace-point-in-time recovery (TSPITR) (archivelogs only), and restore
(archivelogs only), recover commands (archivelogs only) is the flash recovery
area.
Database Area
Flash Recovery Area

7. Flash Recovery Area Space Management
Disk limit is reached and a new file needs to be written into the Flash Recovery Area
Oracle
delete files that
are no longer
required on
disk.
Archive Logs &
Database File
Backups
Flash Recovery Area
Space Pressure occurs
Warning Issued to user 1
RMAN updates
list of files that
may be deleted 2
Each time RMAN creates a file into the flash recovery area, the list of files that are
no longer required on disk, is updated. When the flash recovery area experiences
space pressure or low on free space because there are no files that can be deleted
from the flash recovery area, you are warned that there is a danger of running out
of disk space. The Oracle database server and RMAN continue to create files in
the flash recovery area until 100% of the disk limit is reached. Thus when setting
the DB_RECOVERY_FILE_DEST_SIZE, you must consider whether you have
allocated enough disk space before running out of space or backup to tape. Files
that are obsolete or have been backed up to tape are likely candidates for deletion
to provide for free space.
When files are written into the flash recovery area and space is needed for that file,
the Oracle database deletes a file that is on the obsolete files list. When a file is
written and deleted from the flash recovery area, notification is written into the
alert log.
Note: When flash recovery area used space is at 85% a warning is issued and
when used space is at 97%, a critical warning is issued. These are internal settings
and cannot be changed.
A sample alert log output follows:
WARNING: db_recovery_file_dest_size of bytes
is % used, and has 0 remaining bytes available.
You can issue the following query to determine the action to take:
SQL> select object_type, message_type,
message_level,
2> reason, suggested_action
Backup Files
to be deleted

8. Benefits to Using a Flash Recovery Area
Unifies the storage location of related recovery files
Manages the disk space allocated for recovery files automatically
Simplifies database administrator tasks
Much faster backup
Much faster restore
Much more reliable due to inherent reliability of disks
Disk files that were created by components such as Recovery Manager (RMAN)
and the ARCH process in previous versions had no knowledge of one another or
the sizes of the file system on which the files were created. By allocating a storage
location and unifying related recovery files within a specific area, the Oracle
database server relieves the database administrator from having to manage the disk
files created by these components.
Note: The flash recovery area is also supported by Data Guard. For further
details, please refer to Oracle Database 10g: Maximize Availability - Data Guard
Enhancements eStudy.

9. Change Tracking File Optimizes incremental backups
Track which blocks have changed since last backup
Integrated change tracking file
Changed blocks are tracked as redo is generated
RMAN backup automatically uses changed block list
Flash Recovery Area
Oracle Database 10g allows you to create a block change tracking file that records
the blocks modified since the last backup. RMAN uses the tracking file to
determine which blocks to include in the incremental backup.
Change
Tracking File

10. The Size of the Change Tracking File
Approximately 1/ of the total size of the database
Depends on the number of the threads in RAC environment
Depends on the number of the old backups (max 8 backups are tracked)
The size of the block change tracking file is proportional to:
• Database size in bytes: The block change tracking file contains data
representing every data file block in the database. The data is approximately
1/ of the total size of the database.
• The number of enabled threads: All Real Application Clusters (RAC)
instances have access to the same block change tracking file, however, the
instances update different areas of the tracking file without any locking or
inter-node block swapping. You enable block change tracking for the entire
database and not for individual instances.
• The number of old backups: The block change tracking file keeps a record of
all changes between previous backups, in addition to the modifications since
the last backup. The tracking file retains the change history for a maximum
of eight backups. If the tracking file contains the change history for eight
backups then the Oracle database overwrites the oldest change history
information.
For example, a 500GB database, with only one thread, and having eight backups
kept in the RMAN repository requires a block change tracking file of 20MB.
Note: The minimum size for the block change tracking file is 10MB.

11. Enabling Block Change Tracking
ALTER DATABASE ENABLE BLOCK CHANGE TRACKING
[USING FILE
‘/oracle/u101/changetrack/o1_mf_yzczmrr7_.chg‘];
The Change Tracking Writer (CTWR) process
v$block_change_tracking view
STATUS
FILE
BYTES

12. Incremental Backup and Changed Tracking File Benefits
Faster
– Optimizes incremental backups to only backup those changed blocks directly
– Integrated with DB recovery and logging
Better
– Uses less space since changes are tracked per block group
– RAC enabled
Simpler
Automatically integrates with backup and recovery – zero effort 
In previous releases of the Oracle database when you back up the database using
incremental backups, RMAN had to examine the entire data file to determine
which blocks had changed. Therefore, the time that RMAN takes to perform an
incremental backup is proportional to the size of the data files involved in the
backup.
The block change tracking file enables RMAN to make the incremental backup
time proportional to the amount of content modified since the last backup.

13. Incrementally Updated Backups
RMAN
incremental
backup
Incrementally
Updated Backups
RMAN
RECOVER COPY OF DATAFILE
In Oracle Database 10g, you can use RMAN to apply incremental backups to data
file image copies. With this recovery method, you can use RMAN to recover a
copy of a data file, that is, roll forward (recover) the image copy to the specified
point in time by applying the incremental backups. The benefits of applying
incremental backups to data file image copies are:
• Reduce the time required for media recovery
• No need for you to perform a full image copy after incremental backups
To apply an incremental backup to an image data file copy RMAN requires the
incremental backup files from before the image data file copy until the time at
which you want to stop the recovery process.
If there is more than one version of an image copy recorded in the RMAN catalog
then RMAN automatically uses the latest version of the image copy.
The command to perform this operation is:
RECOVER COPY OF DATAFILE <datafile# or datafile
name>
RMAN> RECOVER COPY OF DATAFILE 10
Initiate Merge
Eliminates the need to perform a whole database backup.
Reduces the time required for media recovery since the image copy is updated with the latest block changes.

14. Eliminate Shrinking Backup Window Syndrome!
Fully automatic disk based backup and recovery
Set it and Forget it
Nightly incremental backup rolls forward recovery area backup
Changed blocks are tracked in production DB
Full scan is never needed
Dramatically faster (20x)
Blocks validated to prevent corruption of backup copy
Use low cost disk array for recovery area
Database Area
Nightly
Apply
Validated
Incremental
Flash Recovery Area
Weekly
Archive
To Tape
Two Independent Disk Systems

15. Oracle Suggested Strategy
Easy & Reliable
Integrates the Oracle DB 10g features
Fast Recovery Options
Backup and Recovery goes from hours to minutes

16. Automated Disk Based Backup & Recovery Benefits
Much faster backup
Just propagate changes to recovery area
Dramatic difference for large databases
Much faster restore
Copy backup files from the Flash Recovery Area
Or simply use the copy in the Flash Recovery Area
Much more reliable due to inherent reliability of disks
Tapes not needed for normal backup/recovery, only for archiving

17. Backup Management List RMAN backups Perform maintenance
View files included in a backup set
Perform maintenance
Remove obsolete backups with a single click

18. What is Transportable Tablespace?
Mechanism to quickly move a tablespace across Oracle databases
Most efficient means to move bulk data between databases.
File is simply copied at OS level
OS copy
File 1
File 2
expdat.dmp 24

19. Oracle10g Cross Platform Transportable Tablespace
Solaris (SPARC)
Open VMS (Intel IA64)
Windows (Intel IA32/64)
Linux (Intel IA32/64)
AIX (PowerPC)
HP-UX (PA-RISC)
Tru64 UNIX (Alpha)
HP-UX (Intel IA64)
Small Endian Platforms
Big Endian Platforms
Simple File Copy Within These
High Speed
File Convert
RMAN

20. Cross Platform Transportable Tablespace Benefits
Fast data distribution in Data Warehousing environment (data marts)
Used for publishing structured data (i.e. catalogs on CDs)
Sharing of read only tablespaces by heterogeneous systems
Allowing a database to be migrated from one platform to another

21. Creating Compressed Backups
Compression of archive logs and backupses using LZ based approach
The compressed backupset is not be usable with pre– Oracle Database 10g
RMAN> BACKUP COMPRESSED BACKUPSET DATABASE;
RMAN> CONFIGURE DEVICE TYPE DISK PARALLELISM 2
BACKUP TYPE TO COMPRESSED BACKUPSET;

22. Other Oracle10g Backup & Recovery Enhancements
Restore tolerates missing or corrupt backup
Automatically fails over to previous backup
Automated recovery through a previous point in time recovery
Recovery through resetlogs
Fully automated tablespace point-in-time recovery
Automatic channel failover on backup or restore
Time window based throttling of backups
Tablespace Rename
Drop Database

23. & Resources Q U E S T I O N S A N S W E R S
HA OTN:
RMAN Discussion Forum otn.oracle.com
MetaLink MetaLink.oracle.com
&
Q U E S T I O N S
A N S W E R S