Re: Downgrade pgsql 17 to pgsql 12 question

On 9/26/25 05:18, Ashish Mukherjee wrote:
> Hello,
>
> I have a strange requirement to downgrade from pgsql 17 to pgsql 12.
> This is because we found in production certain incompatibilities between
> both versions for our database. It should have been caught in testing
> but was not.
>

What are the incompatibilities?

Might be easier to deal with those then doing the below.

> The clean way seems to be text file dump and restore but this would be
> too huge and too slow for our database of 3T. If I use pg_dump v17 and
> then restore with pg_restore v 17 on a pgsql v12 database, is there any
> risk? I tried a small test with a bunch of tables and it worked, but am
> wondering about the pitfalls. I am restoring from the directory format dump.
>
> When I do dump/restore like this for a test table, I get the following
> errors during restore but the table gets restored fine.

> Any input would be appreciated.
>
> Regards,
> Ashish

--
Adrian Klaver
adrian(dot)klaver(at)aklaver(dot)com