Florian Pflug <fgp(at)phlo(dot)org> writes:
> The subtle point here is whether you consider the view from the "outside" (in the sense of what a read-only transaction started at an arbitrary time can or cannot observe), or from the "inside" (what updating transactions can observe and might base their updates on).
> The former case is completely determined by the commit ordering of the transactions, while the latter is not - otherwise serializability wouldn't be such a hard problem.
BTW, doesn't all this logic fall in a heap as soon as you consider
read-committed transactions?
regards, tom lane