What is backup in oracle database?

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 Summary: in this tutorial, you will learn What is backup and what are the types an Oracle Database instances.


There are two types of backup 


1)Logical backup

2)RMAN backup

Logical backup:

Logical backup is nothing but a schemas-level backup and it's collecting all tables and objects level backups.

Example:

Expdp and Impdp Utility 

RMAN backup:

1)Backupsets 

2)Images copies

1)Backupsets 

Whole database backup

Full database backup

Partial database backup


Whole database backup:

Whole backups of a database include the complete contents of all datafile of the database, plus control file,arhived redo log files, and server parameter files 

CMD:

RMAN>backup database plus archivelog;


Full database backup:

Full backups of a database include the complete content of all datafiles of the database plus the controlfile and server parameter file 


RMAN>backup database;


Partial database backup:

Backup of all datafiles for an individual tablespace 

Backup a single datafile.

 RMAN>backup tablespace users;

RMAN>backup datafile 6;


Image Copies:

An image copy backup is the exact copy of the data files including free space.

RMAN>backup as copy database;


Cold or consistent backup :(offline backups)

offline backups are taken while the database is not open.


Hot or Inconsistent backup :(Online backups)

Online backups are taken while the database is open.


RMAN Tools:


RMAN> backup database plus archivelog

RMAN> backup database;

RMAN> backup tablespace users;

RMAN> backup datafile 6;

RMAN> backup archivelog all;


RMAN List Backup Commands:

RMAN>list backup;

RMAN>list backup summary ;

RMAN>list backup by file;

RMAN>list backup of database;

RMAN>list backup of tablespace system;

RMAN>list backup of tablespace users;

RMAN>list backup of datafile 1;

RMAN>list backup of datafile 2;

RMAN>list backup of controlfile;

RMAN>list backup of archivelog all;


                                                        Thanks for your time !!!!


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