在startup 启动数据库后,使用plsql去连接数据库时,
出现ora-12170 错误:
 
在启动、关闭或者重启oracle监听器之前确保使用lsnrctl status命令检查oracle监听器的状态:
1、$lsnrctl status:检查当前监听器的状态
2、$lsnrctl start [listener-name] 启动所有的监听器,可以指定名字来启动特定的监听器
3、$lsnrctl stop [listener-name]  关闭所有的监听器,可以指定名字来关闭特定的监听器
4、$lsnrctl reload  重启监听器,此命令可以代替lsnrctl stop,lsnrctl start
5、lsnrctl hep      可以显示所有可用的监听器命令
常用命令参数:
start - Start the Oracle listener 
stop - Stop the Oracle listener 
status - Display the current status of the Oracle listener 
services - Retrieve the listener services information 
version - Display the oracle listener version information 
reload - This will reload the oracle listener SID and parameter files. This is equivalent to lsnrctl stop and lsnrctl start. 
save_config - This will save the current settings to the listener.ora file and also take a backup of the listener.ora file before overwriting it. If there are no changes, it will display the message “No changes to save for LISTENER” 
trace - Enable the tracing at the listener level. The available options are ‘trace OFF’, ‘trace USER’, ‘trace ADMIN’ or ‘trace SUPPORT’ 
spawn - Spawns a new with the program with the spawn_alias mentioned in the listener.ora file 
change_password - Set the new password to the oracle listener (or) change the existing listener password. 
show - Display log files and other relevant listener information
05-12 07:35