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.klaver@aklaver.com