The good thing is that Apple decides to bundle PostgresSQL 8.4 with OSX Lion which cause conflict if you install Postgres 9.x using brew or Macport. You will likely bump into following error:
$ psql -d postgres -U postgres
psql: could not connect to server: Permission denied
Is the server running locally and accepting
connections on Unix domain socket "/var/pgsql_socket/.s.PGSQL.5432"?
So what’s going wrong here? Because the stock postgresql has higher precedence in PATH.
To fix this, simply make /usr/local/bin highest precendence for $PATH.
Local scope (recommended):
Edit ~/.bash_profile
export PATH=/usr/local/bin:$PATH
System-wide scope:
Edit your /etc/paths and move your /usr/local/bin to the top.
$ sudo nano /etc/paths
/usr/local/bin
/usr/bin
/bin
/usr/sbin
/sbin