Re: [Gnumed-devel] Approaches to maintain clinical data uptime

[Tim Churches]

Karsten Hilbert wrote:

> 1) Slony continually replicates GNUmed database from primary
>    to slave DB on identical secondary 

Have any GNUmeders had any real-life experience with Slony-1? It is hard
to find any stories, good or bad, about it. We were about to test it to
implement a hot spare DB for our NetEpi application (which uses PG
back-end storage), so I read the documentation and realised that Slony
doesn't replicate schema changes - if the schema changes on the master,
you need to a) take the slaves offline b) do a manual dump of the master
and restore it to the slaves c) restart slave synchronisation. That was
a show-stopper for us, since one of the main features is that data
collection forms and their underlying tables can be defined on-the-fly
(I keep wondering whether we should have used an EAV pattern for storage
- Slony would have worked with that..).

Tim C