postgresql version won't change from default

Question

mac os x lion 10.7.4

psql --version -> psql (PostgreSQL) 9.0.5

I want to install latest version and run my rails app with it.

I do

brew install postgresql

it is installed here: /usr/local/Cellar/postgresql/9.1.4  

initdb /usr/local/var/postgres

pg_ctl -D /usr/local/var/postgres -l /usr/local/var/postgres/server.log start

I get:

pg_ctl: another server might be running; trying to start server anyway

running postgres --version

 -> 9.1.4

postgres -p 5433

 postgres does not know where to find the server configuration file.
 You must specify the --config-file or -D invocation option or set the PGDATA environment variable.

Answer 1

Edit /usr/local/var/postgres/postgresql.conf and change the port directive to use a different port number like 5433. Then start the new Pg instance as you did before.

You can now connect to the 9.1 instance by specifying a different port in your Rails configuration.