Re: upgrade and migrate

Greetings,

* Laurenz Albe (laurenz(dot)albe(at)cybertec(dot)at) wrote:
> On Wed, 2019-12-04 at 13:48 +0900, Michael Paquier wrote:
> > On Tue, Dec 03, 2019 at 10:32:22PM +0000, Julie Nishimura wrote:
> > > Hello, what is the best way to migrate from PostgreSQL 8.3.11 on
> > > x86_64-redhat-linux-gnu to PostgreSQL 9.6.16 on x86_64-pc-linux-gnu
> > > server, with minimal downtime?
> > > The caveat is the source has about 80 databases overall almost 30
> > > TB. I could migrate the smallest ones (up to 1 tb) using pg_dump and
> > > pg_restore, but the largest hot database is almost 17 tb, and I am
> > > not sure how to approach this effort in a better and efficient way?
> >
> > pg_upgrade could be one way to go here. That's not the scale pg_dump
> > would be very good at. I would have personally avoided using pg_dump
> > above 10~20GB. Depending on the downtime you are ready to accept,
> > a migration based on Slony could be something to investigate.
>
> Right, Slony is the way to go, since pg_upgrade doesn't support 8.3.
>
> I would upgrade to a version more recent than 9.6.

So... there's a bit of history here. pg_upgrade in 9.4 actually does
support upgrading from 8.3.X. Support for upgrading from 8.3 was
removed in 2209b3923a7afe0b6033ecfea972219df252ca8e.

Thanks,

Stephen