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why not inconsistent backup [message #147122] Tue, 15 November 2005 19:06 Go to next message
lazycat
Messages: 57
Registered: November 2005
Member
dear sir
i want to do Whole Database Backup

my database is in noARCHIVELOG mod
why i only can backup the db in consistent backup

why i can't use the inconsistent backup.

i can't know the reason in the doc
Re: why not inconsistent backup [message #147150 is a reply to message #147122] Tue, 15 November 2005 23:12 Go to previous messageGo to next message
tarundua
Messages: 1080
Registered: June 2005
Location: India
Senior Member
If i understood your question properly then you wants to ask why can't we take hot backups in NOARCHIVELOG mode.

now see this from Oracle docs,

Quote:

Oracle stops recording checkpoints to the datafiles in the tablespace when a tablespace is in backup mode. Because a block can be partially updated at the very moment that the operating system backup utility is copying it, Oracle copies whole changed data blocks into the redo stream while in backup mode. After you take the tablespace out of backup mode with the ALTER TABLESPACE ... END BACKUP or ALTER DATABASE END BACKUP statement, Oracle advances the datafile header to the current database checkpoint.
When you restore a datafile backed up in this way, the datafile header has a record of the most recent datafile checkpoint that occurred before the online tablespace backup, not any that occurred during it. As a result, Oracle asks for the appropriate set of redo log files to apply should recovery be needed. The redo logs contain all changes required to recover the datafiles and make them consistent.


hope this explanation will help you.

[Updated on: Tue, 15 November 2005 23:12]

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Re: why not inconsistent backup [message #147209 is a reply to message #147122] Wed, 16 November 2005 06:19 Go to previous message
Mahesh Rajendran
Messages: 10706
Registered: March 2002
Location: oracleDocoVille
Senior Member
Account Moderator
and long story short,
If you have any data of any worth and you are planning to backup the database, have the database in archivelog mode.

[Updated on: Wed, 16 November 2005 06:20]

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