Based on the docs here:
http://slony.info/documentation/slonyupgrade.html
it would seem that I have to run the exact same version of Slony on all
nodes at all times.  If I want to change that version, I have to update
all nodes simultaneously.

With regards to updating and versions, is this for _any_ version change?
I'm guessing that I can't have a cluster with some 1.1 Slony and some 1.2
Slony.

But, in this particular case, I'm looking at moving some systems from 1.2.6
to 1.2.9.  Do I have to move them all at once, or is the API locked down
in the 1.2 version so that slight disparities are OK?

-- 
Bill Moran
Collaborative Fusion Inc.
http://people.collaborativefusion.com/~wmoran/

wmoran at collaborativefusion.com
Phone: 412-422-3463x4023

****************************************************************
IMPORTANT: This message contains confidential information and is
intended only for the individual named. If the reader of this
message is not an intended recipient (or the individual
responsible for the delivery of this message to an intended
recipient), please be advised that any re-use, dissemination,
distribution or copying of this message is prohibited. Please
notify the sender immediately by e-mail if you have received
this e-mail by mistake and delete this e-mail from your system.
E-mail transmission cannot be guaranteed to be secure or
error-free as information could be intercepted, corrupted, lost,
destroyed, arrive late or incomplete, or contain viruses. The
sender therefore does not accept liability for any errors or
omissions in the contents of this message, which arise as a
result of e-mail transmission.
****************************************************************