> sudo vim /etc/apt/sources.list.d/pgdg.list
add a line for the repositorydeb
> http://apt.postgresql.org/pub/repos/apt/ wily-pgdg main
The mystery bit is the name "wily-pgdg" The first part (wily) should match your Ubuntu release. You can find out the correct name by using:
> lsb_release --all
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 15.10
Release: 15.10
Codename: wily
Import the repository signing key, and update the package lists (cut & paste the following 3 lines)
wget --quiet -O - https://www.postgresql.org/media/keys/ACCC4CF8.asc | sudo apt-key add -
sudo apt-get update
sudo apt-get install -y postgresql-9.5
The last line (with "install") is the one that was missing; everything before that just provides the settings to access the postgresql.org Ubuntu package libraries.
At this point, you should be able to see both your old version of postgresql and the new 9.5 version:
> alias d="ls -ldF"
> d /etc/postgresql/*
drwxr-xr-x 3 postgres postgres 4096 May 26 2015 /etc/postgresql/9.4/
drwxr-xr-x 3 postgres postgres 4096 Jan 8 08:49 /etc/postgresql/9.5/
If you still have PostgreSQL 9.4 installed (as above), the new 9.5 will not be on the default port of 5432, but will instead take the next one (5433). You may wish to edit your postgresql.conf to both rearrange the ports (I put the old postgresql on 5439 and the new one on 5432) and also to copy over any modifications to the parameters you have made:
> sudo vim -d /etc/postgresql/*/main/postgresql.conf
You will also want to copy over any changes to pg_hba.conf:
> sudo vim -d /etc/postgresql/*/main/pg_hba.conf
At this point, all you need to do is restart both servers, and away you go!
> sudo systemctl restart postgresql
> psql --version
psql (PostgreSQL) 9.5.0
Try to log in:
> psql
psql: FATAL: role "alan" does not exist
Doh! We forgot to create our users for the new install:
> sudo -u postgres createuser alan
> sudo -u postgres createdb alan
Viola! Now it works:
> psql
psql (9.5.0)
Type "help" for help.
alan=> select version();
version
----------------------------------------------------------------------------------------------------------
PostgreSQL 9.5.0 on x86_64-pc-linux-gnu, compiled by gcc (Ubuntu 5.2.1-22ubuntu2) 5.2.1 20151010, 64-bit
(1 row)
alan=> \q
Enjoy!!!
