Re: backup and recovery question

Basically, there is no difference...You are playing with fire in both situations. If the database is open while the "offline" or "cold" backup is performed, the backup is invalid and can not be guaranteed usable in a recovery situation. To better understand this, I recommend you familiarize yourself with the checkpoint process and how it relates to datafiles and control files. Upon startup, if any of the datafiles do not agree with the current checkpoint sequence number, then the database will need to be recovered. I would also like to note that Oracle doesn't care or acknowledge UNIX/NT/LINUX time stamps, even if they are the same on all datafiles.

Good Luck,
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In article <3624F6A8.67EF_at_openix.com>,
  tansel_at_openix.com wrote:
> Our system administrator brought up an interesting point:
>
> I know that a backup of Oracle files for a open database
> in NOARCHIVELOG mode will not startup the database. However,
> I was not able to give a good explanation for the following
> question:
>
> What is the difference between a
> database started after a machine crash due to a power loss
> and a database started with all Oracle files copied at exactly
> same point in time for a database running in NOARCHIVELOG mode
> and when the database is open.
>
> Would an Oracle instance recovered using these set of files
> perform an instance recovery at startup?
>
> Thanks..
>
> Tansel
>

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