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Home -> Community -> Usenet -> c.d.o.server -> Re: Crazy mistake in "Oracle Unleashed"
A copy of this was sent to John <john_at_yellowstone.co.uk>
(if that email address didn't require changing)
On Mon, 28 Sep 1998 12:40:21 +0100, you wrote:
>I read the quotes from 'unleashed' as meaning that, the datafiles of the
>tablespaces which had been put into backup mode would not be written to, which
>is true, isn't it, even if the other datafiles would be written to ?
>
No it is not. The datafiles that are being backed up are definitely written to. they are inconsistent, fuzzy and will be in need of recovery in the event they are used for recovery.
>>When you place a tablespace in backup mode, the Oracle instance notes
>>that a backup is being performed and internally compensates for it. As
>>you know, it is impossible to make an authentic copy of a database
>>file that is being written to. On receipt of the command to begin the
>>backup, however, Oracle ceases to make direct changes to the database
>>file.
>
that is an outright mis-statement. it is false. do not believe it.
>Thomas Kyte wrote:
><quote>
>If you are in a situation where your database must be up and running 24 hours
>a day, 7 days a week, you will need to perform inconsistent whole database
>backups. A backup of an open database is inconsistent because portions of the
>database (hence, datafiles in the database) are being modified and written to
>disk while the backup is progressing. The database must be in ARCHIVELOG
>mode to be able to perform open backups.
></quote>
>
>...but not the portions in backup mode ?
Thomas Kyte
tkyte_at_us.oracle.com
Oracle Government
Herndon VA
--
http://govt.us.oracle.com/ -- downloadable utilities
Anti-Anti Spam Msg: if you want an answer emailed to you, you have to make it easy to get email to you. Any bounced email will be treated the same way i treat SPAM-- I delete it. Received on Mon Sep 28 1998 - 08:24:19 CDT
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