Re: psql backward compatibility

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