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Home -> Community -> Usenet -> c.d.o.server -> Re: Need a reality check!
<kal121_at_my-deja.com> wrote in message news:8qolvs$ok5$1_at_nnrp1.deja.com...
> What do you think of the practice of putting ALL OF YOUR TABLESPACES in
> hot backup mode simultaneously? Is this a good idea or bad idea and why?
>
> (Of course I would never do this myself, but what do you all think of
> it?)
it is NOT a good idea to put all of the tablespaces in backup mode at the same time. alter tablespace ... begin backup just before the backup of the datafiles in the tablespace, then copy (backup) the datafiles, and then alter tablespace ... end backup immediately after the backup of the datafiles is complete.
putting all of the tablespaces in hot backup mode at the same time doesn't really buy you anything, unless you have a way to perform the datafile backups in parallel. the downside is a potential for more data written to the redo logs, which can mean reduced performance and more redo to apply in case of a recovery.
putting all of the tablespaces into hot backup mode at the same time does not give you a "consistent" backup, like you can achieve with a "cold" backup. since the database is up and open, changes are still being recorded, and in order to recover using datafiles from a "hot" backup, redo logs must still be applied.
that said, for "small" and "inactive" database, putting all of the tablespaces in backup mode at the same time may not cause you any grief. but you may run into a problem on a "large" or "active" database.
>
> Thank you
>
>
> Sent via Deja.com http://www.deja.com/
> Before you buy.
>
Received on Tue Sep 26 2000 - 21:38:29 CDT
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