This is bothering me to no end. 

I'm setting up a Rails 3.2 environment with Postgresql on my Mac with OS 10.8.2 (Mountain Lion).

I basically followed the directions in the [Railscast](http://railscasts.com/episodes/342-migrating-to-postgresql), and installed postgresql version 9.2.0 via Homebrew. but whenever I do 

```
which psql

```

and 

```
psql --version

```

it always shows me the location and version of the system postgresql that came preinstalled with Mountain Lion (`/usr/bin/psql` and version 9.1.4, respectively), rather than the location and version of the Postgresql that I installed with Homebrew (`/usr/local/bin` and version 9.2.0, respectively).

I also set up a Launch Agent, so that postgresql automatically starts up when I start the system.

I've even tried following the directions from this [blog](http://metacog.tumblr.com/post/28333408639/setting-up-a-development-environment-on-mountain-lion), and I still get the same results when I run `which psql`.

However, when I do:

```
ps -ef | grep postgres

```

I receive the following results:

```
501   556   120   0 Fri02AM ??         0:00.12 /usr/local/bin/postgres -D /usr/local/var/postgres -r /usr/local/var/postgres/server.log

```

Does this mean that I'm running the homebrew version of postgresql?

Do I have to uninstall the system postgresql?