Home » RDBMS Server » Backup & Recovery » tablespace backup mode
tablespace backup mode [message #58061] Tue, 29 July 2003 04:39 Go to next message
shyam
Messages: 25
Registered: January 2001
Junior Member
hi
what will happen when a tablespace taken to backup mode.whether users have any restrictions to access the
dataobjects of the tablespace.Why extra redo is generating when taking a tablespace backup mode
Re: tablespace backup mode [message #58062 is a reply to message #58061] Tue, 29 July 2003 06:06 Go to previous messageGo to next message
Uwe
Messages: 260
Registered: February 2003
Location: Zürich, Switzerland
Senior Member
The Tablespace is freezed, but all actions are stored in the redo-logs. After putting tablespace out of backup Oracle take care for doing all stored actions to that tablespace. Oracle managed this by the sequence-numbers each action will get.
hth
Uwe
Re: tablespace backup mode [message #58133 is a reply to message #58062] Mon, 04 August 2003 06:58 Go to previous message
Deepa
Messages: 269
Registered: November 2000
Senior Member
The tablespace is not freezed during a hotbackup.
Just the DatafileHeaders are freezed with the SCN at the time of beginbackup.the datafiles are updated like normal, only the file header blocks are not updated for checkpoint activity.

When you end the backup Oracle updates the header for the last checkpoint and then knows the tablespace is consistent with this point in time.

When the datafile is restored from a hot
backup, the recovery will begin from the SCN captured during the begin backup
is issued. All changes applied during the hot backup time period will be
rolled forward from the redo logs.
Previous Topic: Hot Backup
Next Topic: Difference between cumulative, differential & incremental Backups
Goto Forum:
  


Current Time: Thu Mar 28 15:45:27 CDT 2024