On 2020-Nov-18, 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?
As others have said: yes.
> 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.
Actually, you can also use pg_upgrade, which might be more convenient,
particularly if your database is large.