Backup Performance via Block Change Tracking | Oracle RMAN ( Recovery Manager ) Backup Tutorials -7

Hi,

I will continue to tell you about the RMAN (Recovery Manager) tool in this seventh article of my tutorial series .

Read Older articles of my rman backup tutorial series before this article with following links.

https://ittutorial.org/2019/03/25/oracle-rman-recovery-manager-backup-tutorials-1/

https://ittutorial.org/2019/03/25/oracle-rman-recovery-manager-backup-tutorials-2/

https://ittutorial.org/2019/03/25/oracle-rman-recovery-manager-backup-tutorials-3/

https://ittutorial.org/2019/03/26/oracle-rman-recovery-manager-backup-tutorials-4/

https://ittutorial.org/2019/03/26/oracle-rman-recovery-manager-backup-tutorials-5/

https://ittutorial.org/2019/03/26/oracle-rman-recovery-manager-backup-tutorials-6/

Block Change Tracking: There is a serious performance problem in case of incremental backup. Because All datafiles are scanned and changing blocks are determined while taking a incremental backup. This performance problem has been fixed with Oracle 10g. With Oracle 10g, changed blocks are written to a file and this backup file is used in incremental backup, a significant performance increase has been achieved in this way. This file is called the Change Tracking File.

We can enable this feature as follows.

[oracle@MehmetSalih ~]$ sqlplus / as sysdba

SQL*Plus: Release 19.0.0.0.0 - Production on Mon Mar 25 17:37:18 2019
Version 19.2.0.0.0

Copyright (c) 1982, 2018, Oracle.  All rights reserved.


Connected to:
Oracle Database 19c Enterprise Edition Release 19.0.0.0.0 - Production
Version 19.2.0.0.0

SQL> select status from v$block_change_tracking;
STATUS
----------
DISABLED






SQL> alter database enable block change tracking using file '/BACKUP/rman_change_tracking_file.f' reuse;

When we enable this feature as above, the blocks that are changed after Full backup will now be written to /BACKUP/rman_change_tracking_file.f. This means that when incremental backup is taken, RMAN should read this file instead of scanning all datafiles one by one. This means a significant performance gain for incremental backup operations. We can disable this feature with the following command.

SQL> ALTER DATABASE DISABLE BLOCK CHANGE TRACKING;

Do you want to learn Oracle Database for Beginners, then read the following articles.

https://ittutorial.org/oracle-database-19c-tutorials-for-beginners/