There are many ways to to upgrade postgres; but, it is not on the fly process for major releases i.e 9.1 to 9.2, and you need to pick what suits you. Ubuntu is using debian packages and when you use it you will have another instance with another point as you have mentioned.
What you need to do
1. either use pg_dumpall /pg_restore in order to load your data in postgresql or pgupgrade. 2. purge 9.1 version 3. reconfigure 9.2 to use port 5432 , ......
From: Muhammad Bashir Al-Noimi <mbnoimi@gmail.com> To: salah jubeh <s_jubeh@yahoo.com> Cc: "pgsql-general@postgresql.org" <pgsql-general@postgresql.org> Sent: Tuesday, July 16, 2013 5:50 PM Subject: Re: [GENERAL] Upgrading from Pg 9.1 to 9.2
The manual pages doesn't talk about install Postgresql from Linux repository for example it doens't mentioed what if I need to use pg_upgrade for bin dir which located in complete different path than Postgresql installer. So I'm lookinhg for specified steps not general information because I don't want to damage my data