pg_ctl -D /usr/local/var/postgres -l /usr/local/var/postgres/server.log start
pg_ctl: another server might be running; trying to start server anyway
server starting

rake db:create all
could not connect to server: No such file or directory
Is the server running locally and accepting

rake aborted!
Don't know how to build task 'all'

me$ psql --version
    psql (PostgreSQL) 9.2.3
    me$ which psql
    /usr/local/bin/psql

ps aux | grep postgres

562 0.6 0.0 2432768 588 s000 S+ 12:45pm 0:00.01 grep postgres

could not connect to server: No such file or directory
    Is the server running locally and accepting
    connections on Unix domain socket "/tmp/.s.PGSQL.5432"?

ls -l /tmp/.s.PGSQL.5432
srwxrwxrwx  1 you  wheel  0 Nov 16 09:22 /tmp/.s.PGSQL.5432

ls: /tmp/.s.PGSQL.5432: No such file or directory

$ grep unix_socket /usr/local/var/postgres/postgresql.conf
#unix_socket_directory = ''     # (change requires restart)
#unix_socket_group = ''         # (change requires restart)
#unix_socket_permissions = 0777     # begin with 0 to use octal notation

$ mkdir /var/pgsql_socket/
$ sudo mkdir /var/pgsql_socket/
$ ln -s /private/tmp/.s.PGSQL.5432 /var/pgsql_socket/

usr/local/var/postgres/server.log

DETAIL:  The data directory was initialized by PostgreSQL version 9.1, which is not compatible with this version 9.2.3.

LOG:  database system was shut down at 2012-02-27 19:18:09 PST
LOG:  autovacuum launcher started
LOG:  database system is ready to accept connections
LOG:  received fast shutdown request
LOG:  aborting any active transactions
LOG:  autovacuum launcher shutting down
LOG:  shutting down
LOG:  database system is shut down
LOG:  database system was shut down at 2012-02-27 21:30:56 PST
LOG:  autovacuum launcher started
LOG:  database system is ready to accept connections
FATAL:  role "shawsome" does not exist
FATAL:  role "shawsome" does not exist
FATAL:  role "shawsome" does not exist
ERROR:  role "myname" already exists
STATEMENT:  CREATE ROLE  MYNAME PASSWORD 'md5b42169a737cea337fe663aa9fbb1df19' SUPERUSER CREATEDB CREATEROLE INHERIT LOGIN;

WARNING:  pgstat wait timeout
WARNING:  pgstat wait timeout
WARNING:  pgstat wait timeout
LOG:  database system was interrupted; last known up at 2012-02-28 21:32:13 PST
LOG:  database system was not properly shut down; automatic recovery in progress
LOG:  record with zero length at 0/1714388
LOG:  redo is not required
LOG:  autovacuum launcher started
LOG:  database system is ready to accept connections
WARNING:  pgstat wait timeout
WARNING:  pgstat wait timeout
FATAL:  database files are incompatible with server
DETAIL:  The data directory was initialized by PostgreSQL version 9.1, which is not compatible with this version 9.2.3.

$ cd /usr/local/bin
$ rm postgres
$ ln -s /Library/PostgreSQL/9.2/bin/postgres postgres
$ rm psql
$ ln -s /Library/PostgreSQL/9.2/bin/psql psql
$ rm pg_ctl
$ ln -s /Library/PostgreSQL/9.2/bin/pg_ctl pg_ctl

$ sudo -u postgres createuser --superuser $USER
$ sudo -u postgres createuser --superuser user_name
$ sudo -u postgres psql postgres

postgres=# password user_name

postgres=# password <username>

$ createdb my_database

/Library/PostgreSQL/9.2/datapostgresql.conf:
listen_addresses = 'localhost'

/Library/PostgreSQL/9.2/datapg_hba.conf:
# "local" is for Unix domain socket connections only
local   all         all                               md5

$ sudo -u postgres pg_ctl -D /Library/PostgreSQL/9.2/data -l /Library/PostgreSQL/9.2/data/server.log start

sudo -u postgres pg_ctl -D /Library/PostgreSQL/9.2/data/ stop -s -m fast

gem 'pg'

$ bundle install

development:
  adapter: postgresql
  encoding: unicode
  host: localhost
  database: my_database
  pool: 5
  username: user_name
  password: password

$ createdb my_database_dev

export PATH=/Applications/Postgres93.app/Contents/MacOS/bin/:$PATH