Re: Visibility regression test

> You could actually serialize all of the commands from one backend,
> against multiple backends, using dblink.

That doesn't help, it changes the connection method but the problem is
still there.

Backend A locks row
Backends B and C are waiting on row
Backend A releases row

The problem is we cannot determine the order that B and C will wake up
in, which makes doing a diff against a standard case difficult.


We don't actually want to serialize the commands as that changes the
test.