On Tue, 2006-03-28 at 15:15 -0600, Scott Marlowe wrote:
> On Tue, 2006-03-28 at 13:51, Rafael Martinez wrote:
> > On Tue, 2006-03-28 at 12:09 -0600, Jim C. Nasby wrote:
> >
> > >
> > > Fortunately, you can use Slony to migrate between versions, greatly
> > > reducing downtime.
> >
> > Yes, this is true, but the problem is that if the database is 'big' and
> > running in an expensive system you need to double your investment only
> > for the upgrade.
> >
> > I am sure we can find another way of doing this that is easier and
> > faster.
>
> Any large, production system should already have replication in place.
>
> If not, you're taking your chances with that big system that make any
> investment questionable. If downtime is a real problem.
You do not need replication in place to run a large system in a
responsible way. I agree that you need redundance in many layers but you
have to stop at some point.
We have for example, some big/expensive disk arrays in our system that
have a lot of redundancy, redundant hot plug power supplies, redundant
hot plug blowers, redundant hot plug cache batteries, redundant hot plug
FC I/O modules, redundant pair of controllers, etc, etc and an expensive
24x7 onsite hardware support. But we do not have an extra disk array
just in case the one in production stops working (it can happen but we
have to trust it won't)
Fast scsi disks in this type of array are not cheap, and the bosses are
not happy if you say that you need the double of space to upgrade the
system, this can be very expensive in a big system.
I work with postgresql every day and I am very happy with it, but this
does not mean I can not see the issues that could be improve to have a
even better open source DBMS. And I think in my humble opinion that
bloated indexes + better upgrade procedures between major releases are
two things that should get improved in the future.
regards,
--
Rafael Martinez, <r.m.guerrero@usit.uio.no>
Center for Information Technology Services
University of Oslo, Norway
PGP Public Key: http://folk.uio.no/rafael/