RMAN BACKUP

 Full db back up level 0

Incremental back up level 1

Full db back up (level 0) has 3 backups

Hot backup ,

cold backup,

 consistence backup.

Incremental backup (level 1) has 2 backups

Level 0 back up it is also known as differential back upit takes less storage

Level 1 back up it is also known as cumulative back up it takes more storage

After 2012 the compressed back up was introduced 

The compressed back up will do the overall data storage/4/2 it is called compressed back up

Eg: overall backup/4/2

             200GB/4/2 = 25 GB

Rman backup: recovery manager backup 

A rman backup is used to store the data completely from day one.

A rman backup is helpful to recover the database at times of database crash.

While we are taking rman backup their multiple files will be backed up in this process

Below are the files which will be backed up they are 

1.control files 2.redolog files 3.data files

4.temp files (temporary files) 5.Archive log files

R-man back up are of 2 types 

Full R-man bkp / full db bkp

Incremental bkp

Full db bkp: a full db backup is nothing but to take the whole database backup and it is called as level 0 backup.

A full db backup is a backup that includes every used data blocks in the file.

A full db backup cannot be a part of incremental backup

(Full db back up taken at weekends Saturday and Sunday)

Full db back up has 3 backups 1) hard back up 2) cold backup

Consistency backup

Hot backup: a hot backup is taken when the database need to run all the time. It’s a online backup

All the files of database are copied and their may be changes to the database during copy

The benefit of taking hard backup is that the data base is available for use while the backup is occuring and one can recover the database to the point in time

Cold backup: a cold backup is done when there are no users activity is going on the database server, it is called as offline backup

This backup will be taken when the database is completely shutdown

All the database files are copied and no changes during this copies are made

Consistent backup: a consistent backup will be taken in mount state i.e 2nd stage ( mount stage )

(The main advantage of this database backup that there is no need to recover the data base after restoration)

Incremental backup: a incremental backup is either level 0 backup, which includes every block in the datafile except blocks that never been used are called as level 1 backup, which includes only those blocks that have been changed since a previous backup was taken.

To connect to R-man backup we should fire command in sql

! rman target/

Sql > ! Rman target /

…………………….

Connected to target database

RMAN>

Company provides scrip to run backup

Tape back up: by using ‘tivoli’ tool the backup will be stored in a tapes ( Tsm team will do this work )