Marsh Ray <marsh5143(at)gmail(dot)com> writes:
> The central question: So if I successfully commit an update
> transaction on one connection, then instantaneously issue a select on
> another previously-opened connection, under what circumstances am I
> guaranteed that the select will see the effects of the update?
If the select is using a snapshot taken later than the commit, it will
see the effects of the update.
The point that the remark about "ill-defined" behavior is trying to make
is that the application could try to compare the results of queries done
using different snapshots, and those results might be different.
regards, tom lane