BACKUP

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我是靠谱客的博主洁净棉花糖，这篇文章主要介绍BACKUP，现在分享给大家，希望可以做个参考。

backup(oracle)

The following table illustrates the main types of physical backups and the non-RMAN methods for performing these backups.

Backup Object	Backup Method	Example
Datafiles	Operating system utility	`% cp df3.f df3.bak`
Archived logs	Operating system utility	`% cp log_1_23.arc log_1_23.bak`
Control files	SQL statement	`SQL> ALTER DATABASE BACKUP CONTROLFILE TO cf1.bak`
Initialization parameter file	SQL statement	`SQL> CREATE PFILE = init.ora.bak FROM SPFILE;`
Network and password files	Operating system utility	`% cp tnsnames.ora tnsnames.bak` `C:/> copy tnsnames.ora tnsnames.bak`
Logical objects (tables, indexes, PL/SQL units)	Export utility	`% export SYSTEM/manager TABLE=hr.emp FILE=emp.dmp`

Consistent and Inconsistent User-Managed Backups

You can use RMAN or operating system commands to make an inconsistent backup or a consistent backup. An inconsistent backup is a backup of one or more database files made while the database is open or after the database has not been shut down normally. A consistent backup is a backup of one or more database files that you make after the database has been shut down normally. Unlike an inconsistent backup, a consistent backup does not require recovery after it is restored.

A consistent whole database backup is the only valid backup option for databases running in NOARCHIVELOG mode, because otherwise redo needed for recovery is not available. In NOARCHIVELOG mode, Oracle overwrites redo records without archiving them first.

If you run the database in ARCHIVELOG mode, then you can back up database files while the database is open. These backups are inconsistent, but as long as you have the necessary archived redo logs you can recover these backups. You can either take a tablespace offline and back up its datafiles, or perform an online backup. An online backup occurs when the tablespace is still online. To perform an online backup, you must begin and end the backup with SQL statements that place the tablespace in and take the tablespace out of backup mode.