Enable or disable block change tracking for RMAN Backup

Block Change Tracking Feature introduce in Oracle 10g which records the modified since last backup and stores the log of it in a block change tracking file. During incremental backups RMAN uses the log file to identify the specific blocks that must be backed up.

Benefits: This improves RMAN performance as it does not need to scan complete data files to detect changed blocks.

Logging of changed blocks is performed by the CTWR process which is also responsible for writing data to the block change tracking file.

For Enable the Block Change Tracking For RMAN

1. Check the status of block change tracking

SELECT filename, status, bytes FROM v$block_change_tracking;

2. Take a location of file and enable the block change tracking

ALTER DATABASE ENABLE BLOCK CHANGE TRACKING USING FILE 'c:\oracle\blockchange.log';

3. Verify the block change tracking status

SELECT filename, status, bytes FROM v$block_change_tracking;

Note:
1. It’s only work under Enterprise edition
2. It’s used only for RMAN Incremental backup
 
Disable block change tracking:

1. Disable the block change tracking

ALTER DATABASE DISABLE BLOCK CHANGE TRACKING;

2. Check the status

SELECT filename, status, bytes FROM v$block_change_tracking;