New features enable block change Tracking-10g

Author: eygle |


English versionArticleSource and author information and this statement]
Link: http://www.eygle.com/archives/2005/03/ooablock_change.html

Block chage tracking is a new feature of Oracle10g. The block change tracking process records data block changes since the last backup and records the changes in the tracking file. RMAN uses this file to determine the changed data to be backed up in the Incremental backup. This greatly improves the backup performance. RMAN can no longer scan the entire file to find the changed data.

 

Therefore, Oracle introduces a new background process, ctwr, which is called change tracking writer. It is used to record changed blocks and write changes to corresponding log files.
To enable tracing, run the following command:

Alter database enable block change tracking using File '/data5/flash_recovery_area/eygle/eygle_block_track.log ';

You can query the current settings:

Select filename, status, bytes from V $ block_change_tracking;

Disable tracing:

Alter database disable block change tracking;

Follow these steps:

 
 
 
 sys as sysdba on 29-Mar-05> alter database enable block change tracking using 
 2 file '/data5/flash_recovery_area /eygle/eygle_block_track.log '; 
 
 database altered. 
 
 sys as sysdba on 29-Mar-05> select filename, status, bytes from V $ block_change_tracking; 
 
 filename 
 enabled 
 Status bytes 
 ---------- 
/data5/flash_recovery_area/eygle/eygle_block_track.log 
 enabled 11599872 
    
 
 sys as sysdba on 29-Mar-05> alter database disable block change tracking; 
 
 database altered. 
 
 sys as sysdba on 29-Mar-05> select filename, status, bytes from V $ block_change_tracking; 
 
 filename 
 bytes 
 Status bytes 
 ---------- 
 
 disabled 
 
 
>