Oracle FAQ Your Portal to the Oracle Knowledge Grid
HOME | ASK QUESTION | ADD INFO | SEARCH | E-MAIL US
 

Home -> Community -> Mailing Lists -> Oracle-L -> Re: ISOLATION LEVEL

Re: ISOLATION LEVEL

From: Niall Litchfield <niall.litchfield_at_gmail.com>
Date: Tue, 10 Jul 2007 11:58:04 +0100
Message-ID: <7765c8970707100358v4ad4edfdq39de7884397c313@mail.gmail.com>


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

--
http://www.freelists.org/webpage/oracle-l
Received on Tue Jul 10 2007 - 05:58:04 CDT

Original text of this message

HOME | ASK QUESTION | ADD INFO | SEARCH | E-MAIL US