問題：
FINAL UPDATE: 最終更新：
I had forgotten to run the initdb command. 我忘了運行initdb命令。
< /FINAL UPDATE> </ FINAL UPDATE>
by running this command 通過運行此命令
ps auxwww | grep postgres
I see that postgres is not running 我看到postgres沒有運行
> 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? 這引出了一個問題：如何啓動postgresql服務器？
update: 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
update 2: 更新2：
The touch was not successful so I did this instead: 觸摸不成功所以我這樣做了：
> 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: 但是當我嘗試啓動rails服務器時，我仍然看到：
Is the server running on host "localhost" and accepting
TCP/IP connections on port 5432?
update 3: 更新3：
> pg_ctl -D /usr/local/var/postgres status
pg_ctl: no server running
update 4: 更新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). 我發現沒有pg_hba.conf（只有pg_hba.conf.sample）所以我修改了樣本並將其重命名（以移除.sample）。 Here are the contents: 以下是內容：
# 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: 但我不明白這個：
> 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: 也：
sudo find / -name postgresql.conf
find: /dev/fd/3: Not a directory
find: /dev/fd/4: Not a directory
update 5: 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.
update 6: 更新6：
this seems odd: 這看起來很奇怪：
> 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: 不過，我這樣做了：
>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
so I did this: 所以我這樣做了：
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
so I tried this: 所以我試過這個：
> 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?" 仍然是相同的“服務器正在運行嗎？” message. 信息。
解決方案：
參考一： https://stackoom.com/question/XSo0參考二： How to start PostgreSQL server on Mac OS X?