Niels Olson <niels.olson at gmail.com> writes:
> I'm a medical student running a wiki on my laptop for notes, it's
> critical to have access offline.
>
> book + computer = good
> book + internet = bad
>
> Offline access is more important than online access. But it would be
> awfully nice to have online access when I can't get to my laptop. I
> have identical versions of Postgres (8.3.6) and wiki software. Would
> Slony be able to help with that? Are there any problems with the
> laptop being a laptop, frequently on small local networks without
> valid NAT?
>
> Should I run it the server as master and the laptop as slave?

Unfortunately, I don't think this is likely to be a very good "use
case" for Slony-I.

As per the documentation...

   "Slony-I is a system intended for data centers and backup sites,
   where the normal mode of operation is that all nodes are available
   all the time, and where all nodes can be secured. If you have nodes
   that are likely to regularly drop onto and off of the network, or
   have nodes that cannot be kept secure, Slony-I is probably not the
   ideal replication solution for you."

The trouble with your scenario is that, with sporadic and changing
connectivity, there would be two notable "emergent problems":

 1.  There are parts of Slony-I that expect regular connectivity, and
     "sporadic" will lead to a buildup of "event crud" that will cause
     poor performance.

 2.  Replication has a certain fragility to it; it sounds likely that
     you would need regular reconfiguration in order to reconnect your
     laptop.

I wish the answers were more favourable, but I'd not want you to be
misled into thinking it would all just "work fine."  It *might* work,
but it is quite possible that it could turn out fairly badly :-(.
-- 
"cbbrowne","@","cbbrowne.com"
http://linuxdatabases.info/info/slony.html
"Consistency  is  the  single  most important  aspect  of  *ideology.*
Reality is not nearly so consistent." - <cbbrowne at hex.net>