I often log into my Ubuntu 12.04.2 server (with Postgres 9.2.4 running with live production data) and see something akin to:
4 packages can be updated. 4 updates are security updates.
This happens about every few days, of course. I'm not interested in automatic updates (the fewer things I can have changing when I'm asleep, the better), but I am interested in always keeping my server up to date, so my question is: When I see output such as that, is it always considered safe to run
apt-get upgrade, or are there times when it can break things. I understand that patches are not always perfect (hence the quoted "always" in the title), but as a general rule, is it assumed safe to run this (esp given this is a database server vs something that just serves CSS files via Nginx)?