PostgreSQL Being Listed on Login Screen

How did you install PostgreSQL?

PostgreSQL v9.0 was downloaded from http://www.postgresql.org/ into the original 13.04 disto in my sda5. This was then DD cloned into my sda6 and dist-upgrade to 13.10. PostgreSQL is needed on my system as I run a Postgres database. It also has to be v9.0 as there are serious limitations to later versions. So, PostgreSQL is 'legitimate' on my system but has only started showing up as a 'user' since the upgrade to Saucy.

Sorry for the time delay, I'm UTC + 8.

> postgres:x:1001:1001:PostgreSQL:/etc/PostgreSQL/9.0:/bin/sh

You created this yourself, didn't you? postgresql-common creates that user as a system user (uid < 500), but this is a "normal" (human) user. For system wide services you should rather do something like "sudo adduser --system postgres".

@ Martin

I don't recall creating the "PostgreSQL" user... just installing the software. The software that creates and uses the PostgreSQL database creates it's own user.

Interestingly, if I go into Ubuntu's Users & Groups, the user 'PostgreSQL' is shown as disabled. The application PostgresSQL is right now happily running and managing my database.

Issue partially resolved.

The 13.04 installation I mentioned was actually cloned from a 12.04LTS partition and I recall that I had problems with permissions
that stopped PostgreSQL from running. The command to change the permissions of the PostgreSQL directory under /etc/ is:

"sudo chown -R postgres:postgres PostgreSQL"

and there's a good chance I screwed that up and inadvertently created a human level user called PostgreSQL. This also meant that I could not delete user PostgreSQL... even tho it was disabled.

I just corrected this (chown) error and have now managed to delete user PostgreSQL which no longer appears on the login screen or the logout/shutdown screen.

Nonetheless, that does not explain how the the 13.04 install did not list PostgreSQL user on the login screen whereas the 13.10 install did.