Re: psql backward compatibility

Thanks for the quick responses!

I'll double-check the configuration. Given your responses it is highly
likely that the older version is still running the server and I'm simply
running the client in 9.6.

On Wed, Nov 18, 2020, 11:16 Adrian Klaver <adrian(dot)klaver(at)aklaver(dot)com> wrote:

> On 11/18/20 8:05 AM, Stephen Haddock wrote:
> > Hello,
> >
> > When upgrading an older version of postgres, version 8.4 for example, to
> > a newer version such as 9.6, does the data have to be migrated
> immediately?
> >
> > It looks like the recommended method is to dump the data, upgrade,
> > initialize a new cluster, and then restore the dumped data into the
> > newer version. My question is whether the data dump and restore must be
> > done immediately. It appears that 9.6 is able to run against the older
> > cluster (DB service starts, queries work, etc), and the data could be
>
> Hmm, missed that. As David said that should not happen and if you are
> running a new binary against an old cluster then you will get corruption.
>
> > migrated days or weeks later. I don't know if that is asking for issues
> > down the line though such as 9.6 corrupting the data due to
> > incompatibilities between the two versions.
> >
> > Thanks!
>
>
> --
> Adrian Klaver
> adrian(dot)klaver(at)aklaver(dot)com
>