> The effects are different, I think, in that there isn't a
> serialization failure in some conflict cases where you would get one
> with actual updates. I found a paper on how to use updates to provide
> serializable transactions in a snapshot database, and I'd have to
> review closely to see how that difference affected the technique. I
> had been thinking that the WAL generation and bloat issues made the
> technique pretty iffy, but if SELECT FOR UPDATE suffices in place of
> most of the proposed updates, it just might be feasible.
In fact, I think SELECT FOR SHARE is enough. That will give you
better concurrency, since it will block only updates and not
concurrent read transactions.
...Robert