Re: Optimistic Locking

"Jim Kennedy" <kennedy-down_with_spammers_at_attbi.com> wrote in message news:<XWDua.777782$3D1.426158_at_sccrnsc01>...
> Or you include all the columns with the prior values in the where clause and
> if you don't update a row then someone changed the data underneath you.

Disadvantage of this is that you have to include all the columns (with :old values) of a table in the where clause... Ok if table is small but bit of an overkill if table has e.g. > 25 columns.

> Advantage of this is you don't have to worry about someone changing data and
> forgetting to update the timestamp.
> Jim
>

With OP's suggestion, you only need a rowid/PK and timestamp to verify if the row has been updated by another user. As far as user forgetting to update the timestamp... this can be easily controlled by either a before insert or update trigger (:new.timestamp := sysdate) or a packaged insert procedure with no direct access to the table.

Regards
/Rauf Sarwar Received on Fri May 09 2003 - 20:57:29 CEST