"Hiroshi Inoue" <Inoue@tpf.co.jp> writes:
> The problem is that session 2 sees a not yet deleted( by session 1)
> session row and an already updated( by session 1) sis_user row at
> the same time. There's no such snapshot that could see both rows.
Running in SERIALIZABLE mode would guarantee consistency, no?
(Session 2 would be forced to roll back and try again, and when
it tried again it would see the session row already gone.)
I doubt that there is any lesser answer that guarantees consistency
across multiple queries.
regards, tom lane