How to check status of PostgreSQL server Mac OS X

The simplest way to to check running processes:

ps auxwww | grep postgres

And look for a command that looks something like this (your version may not be 8.3):

/Library/PostgreSQL/8.3/bin/postgres -D /Library/PostgreSQL/8.3/data

To start the server, execute something like this:

/Library/PostgreSQL/8.3/bin/pg_ctl start -D /Library/PostgreSQL/8.3/data -l postgres.log

You can run the following command to determine if postgress is running:

$ pg_ctl status

You'll also want to set the PGDATA environment variable.

Here's what I have in my ~/.bashrc file for postgres:

export PGDATA='/usr/local/var/postgres'
export PGHOST=localhost
alias start-pg='pg_ctl -l $PGDATA/server.log start'
alias stop-pg='pg_ctl stop -m fast'
alias show-pg-status='pg_ctl status'
alias restart-pg='pg_ctl reload'

To get them to take effect, remember to source it like so:

$ . ~/.bashrc

Now, try it and you should get something like this:

$ show-pg-status
pg_ctl: server is running (PID: 11030)
/usr/local/Cellar/postgresql/9.2.4/bin/postgres

You probably did not init postgres.

If you installed using HomeBrew, the init must be run before anything else becomes usable.

To see the instructions, run brew info postgres

# Create/Upgrade a Database
If this is your first install, create a database with:
     initdb /usr/local/var/postgres -E utf8

To have launchd start postgresql at login:
   ln -sfv /usr/local/opt/postgresql/*.plist ~/Library/LaunchAgents 
Then to load postgresql now:     
   launchctl load ~/Library/LaunchAgents/homebrew.mxcl.postgresql.plist 
Or, if you don't want/need launchctl, you can just run:
    pg_ctl -D /usr/local/var/postgres -l /usr/local/var/postgres/server.log start

Once you have run that, it should say something like:

Success. You can now start the database server using:

postgres -D /usr/local/var/postgres or
pg_ctl -D /usr/local/var/postgres -l logfile start

If you are still having issues, check your firewall. If you use a good one like HandsOff! and it was configured to block traffic, then your page will not see the database.

As of PostgreSQL 9.3, you can use the command pg_isready to determine the connection status of a PostgreSQL server.

From the docs:

pg_isready returns 0 to the shell if the server is accepting connections normally, 1 if the server is rejecting connections (for example during startup), 2 if there was no response to the connection attempt, and 3 if no attempt was made (for example due to invalid parameters).