BLOCK CHANGE TRACKING
Block changing tracking improves the performance of incremental backups by recording changed blocks in the block change tracking file. During an incremental backup, instead of scanning all data blocks to identify which blocks have changed, RMAN uses this file to identify the changed blocks that need to be backed up.
TO ENSURE THE CURRENT PERFORMANCE OF INCREMENTAL BACKUPS:
SQL> col STATUS format a9
SQL> col hrs format 999.99
SQL> select SESSION_KEY, INPUT_TYPE, STATUS,
to_char(START_TIME,’mm/dd/yy hh24:mi’) start_time,
to_char(END_TIME,’mm/dd/yy hh24:mi’) end_time,
elapsed_seconds/3600 hrs from V$RMAN_BACKUP_JOB_DETAILS
order by session_key;
The above command will show the performance of daily incremental backups.
i.e., How many hours the database backup is running before enabling the block change tracking.
TO ENSURE THE BLOCK CHANGE TRACKING IS ENABLED IN THE DATABASE:
SQL> select status, filename from v$block_change_tracking;
It will show the block change tracking is enabled in our database or not.
If it shows disabled, we want to enable the parameter by issue the below command.
SQL> alter database enable block change tracking;
NOTE:- After enables the BLOCK_CHANGE_TRACKING, wait for a day to complete the database backup. Then issue the above command to ensure the incremental backup performance.
It will show you the positive differences compares to the earliest performance.
