I'm fully aware why it's an issue with official image. But even with debian (or any other "packaging") there are hoops to be hopped through due to said missing upgrade handling which IMHO is very annoying.

They do handle minor versions upgrade so the code handling upgrading is there but devs seems to be quite adamant against adding major version upgrade. I (well, a lot of people judging from votes and comments in https://github.com/docker-library/postgres/issues/37 and stars in https://github.com/tianon/docker-postgres-upgrade) would love that, and only between subsequent version would be more than enough…

> They do handle minor versions upgrade so the code handling upgrading is there but devs seems to be quite adamant against adding major version upgrade

Minor versions of PostgreSQL have constraints that major versions don't have; in that minor versions in principle don't see new features added. This allows minor versions of the same major release to run against the same data directory without modifications.

However.

Major versions add those new features, at the cost of changes to internals that show up in things like catalog layout. This causes changes in how on-disk data is interpreted, and thus this is incompatible, and unlike minor releases this requires specialized upgrade handling.

I suggest you look into what pg_upgrade actually does because the "code handling upgrading" does not exist other than as pg_upgrade. And writing it would be a ton of work and would likely halt a lot of innovation in PostgreSQL and make it no longer a competitive database unless someone does a major re-architecting of PostgreSQL which likely would break all extensions.

The issue causing it is how PostgreSQL has implemented the system catalog.