2010/7/13 Silvio Brandani <silvio(dot)brandani(at)tech(dot)sdb(dot)it>:
> We need to upgrade the postgres running on our production system under Red
> Hat Enterprise Linux Server release 5.1 from version 8.1.21 to version
> 8.3.6.
>
> we could have a stop/maintenance window of 3/4 our the sum of size of
> databases is around 1G .
> Which is the best practice to execute such upgrade with possible rollback
> operation to gain in 3/4 hour this job ??
> Any suggestion higly appreciated
We use slony to upgrade in place. total downtime is measured in
seconds, minutes at the most.