Re: ISOLATION LEVEL

Where does your requirement/code come from. Is your code not a logical transaction? If so why do you need to see wrong/old data at later stages. If it is a logical transaction then make it a single transaction and you'll only see consistent data.

Something doesn't sound quite right but without seeing either your code or your requirements it's somewhat tricky to tell.

On 7/10/07, DBA Deepak <oracle.tutorials_at_gmail.com> wrote:
>
> Hi All,
>
> Have a doubt on transaction isolation.
>
> My requirement is to query several tables several times inside a piece of
> code. The data needs to be consistent across multiple queries. The
> underlying tables are subjected to change during the execution of the piece
> of code.
>
> I have two options to be used inside my piece of code to achieve
> consistent/repeatable reads.
>
> 1> to use SET TRANSACTION READ ONLY;
> 2> to use ALTER SESSION SET ISOLATION_LEVEL=SERIALIZABLE;
>
> My question is which option is preferable and why? Is there any
> performance issues with one of these in the above mentioned scenarios?
>
> Need your valuable feedback.
>
> --
> Regards,
>
> Deepak
> Oracle DBA
>

-- 
Niall Litchfield
Oracle DBA
http://www.orawin.info

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