On tis, 2011-08-16 at 20:35 -0400, Tom Lane wrote:
> In fact, now that I think about it, setting the transaction snapshot
> from a utility statement would be functionally useful because then you
> could take locks beforehand.
Another issue is that in some client interfaces, BEGIN and COMMIT are
hidden behind API calls, which cannot easily be changed or equipped with
new parameters. So in order to have this functionality available
through those interfaces, we'd need a separately callable command.