Oracle Hot Backup

-- ======================================

-- OracleHot Backup

-- ======================================

 

OracleHot Backup means that the database is inOpenTo back up database data files, control files, parameter files, and password files.

Hot Backup is a backup recovery method based on user management.RMANBackup is a common backup method.

 

I. Hot Backup Process

Freeze block Header-->ControlSCNNo change during Backup

Physical copy

Unfreeze block Header-->LetSCNChangeable(WhenSCNAfter the restoration, the system automatically updatesSCNTo the latest status)

 

2. Database-based hot standby

Alter Database Begin Backup;

Copy allDatafileTo the Backup Directory

Alter Database End Backup;

 

Iii. Hot Backup Based on tablespace

AlterTablespace tablespace_nameBegin Backup;

CopyTablespace_nameTablespace data files to the backup directory

AlterTablespace tablespace_nameEnd Backup;

 

AlterTablespace tablespace_nameBegin BackupCompleted tasks

Check Point event, Check Point notificationDBWnWrite all the dirty data in the tablespace to the disk.

When the current checkpoint event is frozen in the data file headerSCNNo.

Complete images of all changed data blocks(Before and after modification)WrittenRedoLogMedium

Allow normal read/write of data in the tablespace

 

We recommend that you use table space-based hot standby to minimize the impact on system performance.

 

Iv. Hot Backup of Control Files

Alter Database BackupControlfileTo '<Dir>';--Full backup of Control Files

Alter Database BackupControlfileToTraceAs '<Dir>'--The statement used to create the control file. Some information is lost.

Control File changes

Alter Database[Add | drop] logfile

Alter Database[Add | drop] logfile member

Alter Database[Add | drop] logfileGroup

Alter Database[Archivelog | noarchivelog]

Alter DatabaseRenameFile

CreateTablespace

AlterTablespace [add | rename] datafile

AlterTablespace [read write | read only]

DropTablespace