PostgreSQL 啟動失敗解決
機房斷電了，PostgreSQL 起不起來了。
[root@scoder19 9.3]# service postgresql-9.3 start
Starting postgresql-9.3 service: [FAILED]
日志文件（/var/lib/pgsql/9.3/pgstartup.log）：報錯如下：
< 2016-07-11 18:12:54.861 CST >FATAL: data directory "/var/lib/pgsql/9.3/data" has group or world access
< 2016-07-11 18:12:54.861 CST >DETAIL: Permissions should be u=rwx (0700).
< 2016-07-11 18:42:30.144 CST >FATAL: data directory "/var/lib/pgsql/9.3/data" has group or world access
< 2016-07-11 18:42:30.144 CST >DETAIL: Permissions should be u=rwx (0700).
< 2016-07-11 18:48:57.110 CST >FATAL: data directory "/var/lib/pgsql/9.3/data" has group or world access
< 2016-07-11 18:48:57.110 CST >DETAIL: Permissions should be u=rwx (0700).
< 2016-07-11 18:50:03.962 CST >FATAL: data directory "/var/lib/pgsql/9.3/data" has group or world access
< 2016-07-11 18:50:03.962 CST >DETAIL: Permissions should be u=rwx (0700).
< 2016-07-11 18:50:53.958 CST >FATAL: data directory "/var/lib/pgsql/9.3/data" has group or world access
< 2016-07-11 18:50:53.958 CST >DETAIL: Permissions should be u=rwx (0700).
< 2016-07-11 18:53:52.351 CST >FATAL: data directory "/var/lib/pgsql/9.3/data" has group or world access
< 2016-07-11 18:53:52.351 CST >DETAIL: Permissions should be u=rwx (0700).
< 2016-07-11 18:56:00.421 CST >FATAL: data directory "/var/lib/pgsql/9.3/data" has group or world access
< 2016-07-11 18:56:00.421 CST >DETAIL: Permissions should be u=rwx (0700).
< 2016-07-11 19:07:15.219 CST >FATAL: data directory "/var/lib/pgsql/9.3/data" has group or world access
< 2016-07-11 19:07:15.219 CST >DETAIL: Permissions should be u=rwx (0700).
< 2016-07-11 19:09:04.421 CST >FATAL: data directory "/var/lib/pgsql/9.3/data" has group or world access
< 2016-07-11 19:09:04.421 CST >DETAIL: Permissions should be u=rwx (0700).
< 2016-07-11 19:27:05.271 CST >FATAL: data directory "/var/lib/pgsql/9.3/data" has group or world access
< 2016-07-11 19:27:05.271 CST >DETAIL: Permissions should be u=rwx (0700).
< 2016-07-11 20:03:10.555 CST >FATAL: data directory "/var/lib/pgsql/9.3/data" has group or world access
< 2016-07-11 20:03:10.555 CST >DETAIL: Permissions should be u=rwx (0700).
< 2016-07-11 20:11:01.442 CST >FATAL: data directory "/var/lib/pgsql/9.3/data" has group or world access
原因是應該是 文件夾 “/var/lib/pgsql/9.3/data”權限錯誤， 權限應該是 rwx (0700)。
解決方法：
切換到 具有root權限的用戶，
（1）先把文件夾 “/var/lib/pgsql/9.3/data” 的用戶所屬組，給postgres 用戶：
進入/var/lib/pgsql/9.3目錄
cd /var/lib/pgsql/9.3
chown -R postgres:postgres data
（2）把data目前的所有文件及子目錄文件權限改成： rwx (0700)
chmod -R 0700 data
重啟PostgreSQL 數據庫，問題解決。