On Sun, Mar 04, 2007 at 14:55:47 +0200, Hannu Krosing <hannu@skype.net> wrote:
>
> UPDATE
> IF NOT FOUND THEN
> INSERT
> IF DUPLICATE KEY THEN
> UPDATE
> END IF
> END IF
I believe it is possible for the above to fail. For example another
transaction could create a matching record between the update and insert
and then another transaction could delete it between the insert and the
second update.