Is updating a postgres database from an unsupported version important?

Question

So far, I see only two reasons that make me consider an update from Postgres 9.4 (which is already an unsupported version).

1. I want to use Django 3.1 for the development of a new web and this new version of Django does not support Postgres 9.4 anymore.
2. I would have a new functionality and maybe an improved performance.

Are there other, maybe more important reasons why to update? Should I care that it is an unsupported verion? And if yes, is it worth to update all the way to the newest stable version?

Answer 1

See the PostgreSQL project's statement on “ why update ”:

We always recommend that all users run the latest available minor release for whatever major version is in use.

[...]

While upgrading will always contain some level of risk, PostgreSQL minor releases fix only frequently-encountered bugs, security issues, and data corruption problems to reduce the risk associated with upgrading. For minor releases, the community considers not upgrading to be riskier than upgrading .

Now if you are running an unsupported version, there are no longer minor releases, so you get no fixes for the aforementioned security issues and data corruption problems.

That is a good idea only if your data are not important to you.

There is the wide-spread idea that if a database has run without problems for so many years, then it will continue to run without problems in the forseeable future. That is not true:

• Some data corruption problems don't manifest immediately. It may take a transaction ID wraparound or an unusual timing in certain operations to reveal a problem that has been dormant so far.

• Databases that are never upgraded are often run on old hardware, which is the main reason for data corruption. Indeed, if you want to upgrade the hardware but not change the software, you may find it increasingly difficult to find the old versions of the programs to install. Old software may not even run on new hardware.

• The majority of corrupted databases I have had the mixed pleasure of dealing with in my professional career were running old, unsupported versions of PostgreSQL. That cannot be a coincidence.