最后更新:

我忘了运行initdb命令。

---

通过运行这个命令

ps auxwww | grep postgres

我看到postgres没有运行

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

这就提出了一个问题:

如何启动PostgreSQL服务器?

更新:

> 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

更新2:

触摸没有成功，所以我做了这个:

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

但是当我试图启动Ruby on Rails服务器时，我仍然看到这个:

服务器是否运行在主机“localhost”上并接受 5432端口上的TCP/IP连接?

更新3:

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

更新4:

我发现没有任何pg_hba.conf文件(只有文件pg_hba.conf.sample)，所以我修改了示例并重命名它(删除.sample)。内容如下:

 # IPv4 local connections:
 host    all             all             127.0.0.1/32           trust
 # IPv6 local connections:
 host    all             all             ::1/128                trust

但我不明白:

> 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

另外:

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

更新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.

更新6:

这似乎很奇怪:

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

不过，我确实这么做了:

>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

所以我这样做了:

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

所以我试着这样做:

> 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

我仍然得到相同的“服务器正在运行吗?”消息。

> ./pg_ctl -D /Library/PostgreSQL/<version>/data start 
  pg_ctl: could not open PID file "/Library/PostgreSQL/<version>/data/postmaster.pid": Permission denied 

sudo -u postgres ./pg_ctl start -D /Library/PostgreSQL/<version>/data/ 
sudo -u postgres ./pg_ctl stop -D /Library/PostgreSQL/<version>/data/
sudo -u postgres ./pg_ctl reload -D /Library/PostgreSQL/<version>/data/ 

/usr/local/var/postgres/server.log

FATAL:  data directory "/usr/local/var/postgres" has group or world access
DETAIL:  Permissions should be u=rwx (0700).

chmod 0700 /usr/local/var/postgres

mkdir db
initdb db -E utf8
createdb public

postgres -d db

psql -d public