[castorp]

> One important point is that Uber wrote this running on Postgres 9.2. The latest Postgres release is now 12.4

Just a minor nitpick: Postgres changed the version numbering scheme with version 10. So 9.4 was a major release, but 12.4 marks a minor (bugfix) release.

If you want to name minor releases it would be e.g. 9.4.26 vs. 12.4. If you want to compare major versions it would be 9.4 vs. 12

[takeda]

Basically the first number didn't really have any meaning, so it was removed, so the major versions (which I believe are released once a year) are:

9.2 (released in 2012)

9.3

9.4

9.5

9.6

10

11

12

13 (about to be released this year?)

That's still a lot of versions in between, each of them as new functionality and requires converting the database to upgrade.