Earlier quoted context omitted.
That is mostly an issue with the official docker image, not a PostgreSQL issue. Upgrading to a new major is easy if you use the Debian packages and is fine with a couple of minutes downtime. There is no reason a docker image could not do the same. The issue with PostgreSQL which the Debian packages handle fine but the Docker Hub's image does not is that you need both the executables for the old and the new major vers…
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 htt…
The issue causing it is how PostgreSQL has implemented the system catalog.