RMAN Block Change Tracking in 19C Database
Before the start the BCT let’s take quick recap for incremental backup first Incremental backup The goal of an incremental backup is to back up only those data blocks that have changed since a previous backup. During incremental backup, RMAN checks every data block in all datafiles of the database and compares its SCN number with the SCN value that is at the incremental 0 backup. If the first value is greater than the second, it means that the data block has been changed after the last backup and needs to be backed up, so RMAN writes it to the backup file. This procedure is done for every data block in the database So as RMAN checks all data blocks and writes down only changed ones during incremental backup It takes more time for the checking process so BTC introduced in 10G Block Change Tracking (BCT) Oracle 10gR2 database introduced Block change tracking (BTC) It is used to improve the incremental backup performance by recording changed blocks in each datafile in