when instance recovery is done then all redo log file data is roll forword.
In roll forword phase it is written to the datafile whether it is commited
or un commited. at this point rollback segment is populated.Rollback segment
entry will be done if not present for un commited data. then rollback is
done. At this point of time, datafile may have un commited data also. as
blocks are needed in buffer cache , data is rolled back.
Regards,
Rajendra Prakash
----- Original Message -----
From: Deepak Kulkarni <deepak.[Email Address Removed] LazyDBA.com Discussion <[Email Address Removed] Monday, September 30, 2002 4:16 PM
Subject: Commtted DATA


> Hi DBAs,
>
> How does a commit ensures that 'Committed Data' is available when a
database
> is reopened after crash ?
>
> Bcoz commit only ensures that data is written to Redo logs & not to data
> files !!
>
> Kindly help.
>
> Regards
> Deepak Kulkarni
> Sr. Software Engineer
> > CyberTech Systems and Software Ltd.
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> >
> >
> >
> >
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