Disconnected editing - versioning of databases

Hi All

I'm wondering if anyone can share any insights or experience with
temporary versions of databases, allowing "disconnected editing"
during Internet downtime.

The use-case is that I run a Postgres database, hosted in the UK, but
used by scientists in several other countries - Ecuador, Vietnam,
Kenya and Indonesia.
Unfortunately the connectivity between the UK and these countries is
flaky at best - perhaps usable 70% of the time. This means a lot of
wasted time for technicians and scientists working at remote
locations.

I could potentially run a database in each of these countries and
provide 100% uptime, obviously raising the issue of version conflicts
that would require hand-merging. Do people think this is feasible, or
a total non-starter? Performance is not an issue. Development time is
:)

Cheers

Will T