Thursday, February 11, 2010

Oracle Block change Tracking

Oracle Block change Tracking
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Oracle Block change Tracking improves the incremental Backup performance and
is used to record changed blocks in each datafile in a change tracking file.
If change Tracking is enabled, RMAN uses block change tracking file to identify
changed blocks for incremental backups and avoids full datafile scans during the backup.Block change tracking feature introduce in Oracle 10g R1. By default,
the Block change tracking file is created as Oracle managed file in
DB_CREATE_FILE_DEST.By default, Oracle will not record block change information.
You can Enable or disable the change tracking when the database is open or mounted.

Enable and Disable Block Change Tracking:
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SQL>ALTER DATABASE ENABLE BLOCK CHANGE TRACKING;

Run the below command to create change tracking file in a specified location.
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SQL> ALTER DATABASE ENABLE BLOCK CHANGE TRACKING
USING FILE 'D:\oradata\orcl\block_change_track.ora' REUSE;

Run the below command to disable block change tracking
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SQL> ALTER DATABASE DISABLE BLOCK CHANGE TRACKING;

Run the below Query to monitor the status of block change tracking
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SQL> SELECT FILE,STATUS,BYTES FROM V$BLOCK_CHANGE_TRACKING;

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