macos - How to start PostgreSQL server on Mac OS X?

FINAL UPDATE:

I had forgotten to run the initdb command.

< /FINAL UPDATE>

by running this command

ps auxwww | grep postgres

I see that postgres is not running

> ps auxwww | grep postgres

remcat          1789   0.0  0.0  2434892    480 s000  R+   11:28PM   0:00.00 grep postgres

this raises the question:
How do I start the postgresql server?

update:

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

sh: /usr/local/var/postgres/server.log: No such file or directory

update 2:

The touch was not successful so I did this instead:

> mkdir /usr/local/var/postgres
> vi /usr/local/var/postgres/server.log
> ls /usr/local/var/postgres/          

server.log

But when I try to start rails server, I still see this:

Is the server running on host "localhost" and accepting
TCP/IP connections on port 5432?

update 3:

> pg_ctl -D /usr/local/var/postgres status
pg_ctl: no server running

update 4:

I found that there WAS NO pg_hba.conf (only pg_hba.conf.sample) so I modified the sample and renamed it (to remover the .sample). Here are the contents:

 # IPv4 local connections:

 host    all             all             127.0.0.1/32           trust
 # IPv6 local connections:
 host    all             all             ::1/128                trust

but I don't understand this:

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

pg_ctl: no server running

also:

sudo find / -name postgresql.conf
find: /dev/fd/3: Not a directory
find: /dev/fd/4: Not a directory

update 5:

sudo pg_ctl -D /usr/local/var/postgres -l /usr/local/var/postgres/server.log start
Password:
pg_ctl: cannot be run as root
Please log in (using, e.g., "su") as the (unprivileged) user that will own the server process.

update 6:

this seems odd:

> egrep 'listen|port' /usr/local/var/postgres/postgresql.conf
egrep: /usr/local/var/postgres/postgresql.conf: No such file or directory

though, I did do this:

>sudo find / -name "*postgresql.conf*"
find: /dev/fd/3: Not a directory

find: /dev/fd/4: Not a directory
/usr/local/Cellar/postgresql/9.0.4/share/postgresql/postgresql.conf.sample
/usr/share/postgresql/postgresql.conf.sample

so I did this:

egrep 'listen|port' /usr/local/Cellar/postgresql/9.0.4/share/postgresql/postgresql.conf.sample 
#listen_addresses = 'localhost'     # what IP address(es) to listen on;
#port = 5432                # (change requires restart)

                # supported by the operating system:
                #   %r = remote host and port

so I tried this:

> cp /usr/local/Cellar/postgresql/9.0.4/share/postgresql/postgresql.conf.sample /usr/local/Cellar/postgresql/9.0.4/share/postgresql/postgresql.conf        
> cp /usr/share/postgresql/postgresql.conf.sample /usr/share/postgresql/postgresql.conf 

still getting the same "Is the server running?" message.

Answer

The Homebrew package manager includes launchctl plists to start automatically. For more information run brew info postgres.

Start manually:

pg_ctl -D /usr/local/var/postgres start

Stop manually:

pg_ctl -D /usr/local/var/postgres stop

Start automatically:

"To have launchd start postgresql now and restart at login:"

brew services start postgresql

---

What is the result of pg_ctl -D /usr/local/var/postgres -l /usr/local/var/postgres/server.log start?

What is the result of pg_ctl -D /usr/local/var/postgres status?

Are there any error messages in the server.log?

Make sure tcp localhost connections are enabled in pg_hba.conf:

# IPv4 local connections:
host    all             all             127.0.0.1/32            trust

Check the listen_addresses and port in postgresql.conf:

egrep 'listen|port' /usr/local/var/postgres/postgresql.conf

#listen_addresses = 'localhost'     # what IP address(es) to listen on;
#port = 5432                # (change requires restart)

---

Cleaning up

Postgres was most likely installed via Homebrew, Fink, MacPorts or the EnterpriseDB installer.

Check the output of the following commands to determine which package manager it was installed with:

brew && brew list|grep postgres
fink && fink list|grep postgres

port && port installed|grep postgres