发布网友 发布时间:2022-04-19 18:23
共1个回答
热心网友 时间:2023-06-22 01:36
1. 启动数据库服务器(posgres用户):
[postgres@localhost bin]$ postgres -D /opt/postgresql/data/ > /opt/postgresql/log/pg_server.log 2>&1 &
[1] 4508
当然如果设置了环境变量
PGDATA=/opt/postgresql/data
export PGDATA
后,可使用pg_ctl工具进行启动:
[postgres@localhost log]$ pg_ctl start -l /opt/postgresql/log/pg_server.log
pg_ctl: another server might be running; trying to start server anyway
pg_ctl: could not start server
Examine the log output.
[postgres@localhost log]$
因为之前已经启动,所以打印“another server might be running”。此时,查看日志,有如下信息:
[postgres@localhost log]$ cat pg_server.log
FATAL: lock file "postmaster.pid" already exists
HINT: Is another postmaster (PID 4491) running in data directory "/opt/postgresql/data"?
[postgres@localhost log]$
当然,最简的.启动方式是:
[postgres@localhost ~]$ pg_ctl start
server starting
[postgres@localhost ~]$ LOG: database system was shut down at 2011-07-09 13:58:00 CST
LOG: autovacuum launcher started
LOG: database system is ready to accept connections
如果要在操作系统启动时就启动PG,可以在/etc/rc.d/rc.local 文件中加以下语句:
/opt/postgresql/bin/pg_ctl start -l /opt/postgresql/log/pg_server.log -D /opt/postgresql/data
2.关闭服务器
最简单方法:
[postgres@localhost ~]$ pg_ctl stop
waiting for server to shut down.... done
server stopped
与Oracle相同,在关闭时也可采用不同的模式,简介如下:
SIGTERM
不再允许新的连接,但是允许所有活跃的会话正常完成他们的工作,只有在所有会话都结束任务后才关闭。这是智能关闭。
SIGINT
不再允许新的连接,向所有活跃服务器发送 SIGTERM(让它们立刻退出),然后等待所有子进程退出并关闭数据库。这是快速关闭。
SIGQUIT
令 postgres 向所有子进程发送 SIGQUIT 并且立即退出(所有子进程也会立即退出),而不会妥善地关闭数据库系统。这是立即关闭。这样做会导致下次启动时的恢复(通过重放 WAL 日志)。我们推荐只在紧急的时候使用这个方法。
SIGKILL
此选项尽量不要使用,这样会阻止服务器清理共享内存和信号灯资源,那样的话你只能在启动服务器之前自己手工做这件事。另外,SIGKILL 直接把 postgres 杀掉,而不会等它把信号中继给它的子进程,因此我们还需要手工杀掉每个独立子进程。
使用方法举例:
[postgres@localhost ~]$ pg_ctl stop -o SIGTERM
LOG: received smart shutdown request
LOG: autovacuum launcher shutting down
waiting for server to shut down....LOG: shutting down
LOG: database system is shut down
done
server stopped
[postgres@localhost ~]$
最快速关闭方法:kill postgres 进程
[postgres@localhost ~]$ kill -INT `head -1 /opt/postgresql/data/postmaster.pid`
[postgres@localhost ~]$ LOG: received fast shutdown request
LOG: aborting any active transactions
LOG: autovacuum launcher shutting down
LOG: shutting down
LOG: database system is shut down
附:postgre启动后的进程,如下:
[postgres@localhost ~]$ ps -ef|grep post
root 4609 4543 0 13:57 pts/2 00:00:00 su - postgres
postgres 4610 4609 0 13:57 pts/2 00:00:00 -bash
postgres 4724 1 0 14:08 pts/2 00:00:00 /opt/postgresql/bin/postgres
postgres 4726 4724 0 14:08 ? 00:00:00 postgres: writer process
postgres 4727 4724 0 14:08 ? 00:00:00 postgres: wal writer process
postgres 4728 4724 0 14:08 ? 00:00:00 postgres: autovacuum launcher process
postgres 4729 4724 0 14:08 ? 00:00:00 postgres: stats collector process
postgres 4752 4610 0 14:11 pts/2 00:00:00 ps -ef
postgres 4753 4610 0 14:11 pts/2 00:00:00 grep post
[postgres@localhost ~]$