[Persistence-sig] A simple Observation API

[Jeremy Hylton]

>>>>> "PJE" == Phillip J Eby <pje@telecommunity.com> writes:

  PJE> Well, the example implementation I wrote took care of all of
  PJE> that, quite elegantly I thought.  But for my purposes, it's
  PJE> sufficient as long as _p_changed is set after the last
  PJE> modification that occurs.  It's okay if it's also set after
  PJE> previous modifications.  It just must be set after the last
  PJE> modification, regardless of how many other times it's set.

  PJE> This requirement on my part has strictly to do with data
  PJE> managers that write to other data managers, in the context of
  PJE> the transaction API I proposed.

Can you explain how _p_changed is used outside of transaction control?
I still don't understand how the timing of _p_changed affects things.

Jeremy