Shulou(Shulou.com)05/31 Report--

This article mainly explains "what are the user-managed backups". The content of the explanation is simple and clear, and it is easy to learn and understand. Please follow the editor's train of thought. Let's study and learn "what are user-managed backups"?

1. Backup database

Concept: refers to backing up all data files and control files of the database, as well as parameter files and password files

Note: when backing up the database, do not back up the redo log.

1.1 consistent backup

Concept: database consistent backup refers to the method of backing up all data files and control files after shutting down the database. When the database is shut down normally using the SHUTDOWN command, the current SCN values of all database files are exactly the same, so the closed database backup is called database consistent backup or cold backup.

Applicable: ARCHIVELOG, NOARCHIVELOG

Select name from v$datafile union select name from v$controlfile

Shutdown immediate

Copy file

Startup

1.2 inconsistent backup

Concept: refers to the method of backing up all data files and control files of a database in OPEN state. Because the content of the database can change at any time in the OPEN state, the current SCN values of different database files are completely different, so the database backup when it is opened is called database inconsistent backup.

Applicable: ARCHIVELOG mode.

Select name from v$datafile

Alter database begin backup

Copy file

Alter database backup controlfile to''

Alter database end backup

Alter system archive log current

two。 Backup tablespace

Concept: refers to the method of backing up data files when the database is in the OPEN state.

Applicable: ARCHIVELOG mode.

Note: you can back up all data files in the table space, or you can back up a data file in the table space.

2.1 offline backup

Concept: the process of backing up all data files or individual data files of a table space when the table space is in the OFFLINE state.

Applicable: ARCHIVELOG mode.

Advantage: fewer redo logs are generated.

Disadvantages: it will affect the business operation of the tablespace. (because neither SYSTEM nor the UNDO tablespace being used can be offline)

Select file_name from dba_data_files where tablespace_name='USERS'

Alter tablespace users offline

Copy file

Alter tablespace users online

2.2 online backup

Concept: the process of backing up all data files or individual data files of a table space when the table space is in the ONLINE state.

Applicable: ARCHIVELOG mode.

Advantages: it does not affect business operations on the tablespace.

Cons: more REDO information and archive information will be generated.

Select file_name from dba_data_files where tablespace_name='USERS'

Alter tablespace users begin backup

Copy file

Alter tablespace users end backup

Thank you for your reading. The above is the content of "what are user-managed backups?" after the study of this article, I believe you have a deeper understanding of what user-managed backups have. Specific use also needs to be verified in practice. Here is, the editor will push for you more related knowledge points of the article, welcome to follow!

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.