sql里面保存屏幕输出的内容的命令：

spool /tmp/a.txt

******执行任何sql操作

spool off

ho cat /tmp/a.txt

启动sqlplus工具：

su - oracle

$lsnrctl status/start/stop 查看监听状态以及启动停止监听

sqlplus / as sysdba

sqlplus工具启动成功，进入SQL提示符!

SQL>

进入SQL提示符要做的第一件事是登录：

SQL>conn scott/tiger

查看当前使用哪一个用户登录的

SQL> show user

在命令行为scott用户解锁:

SQL>conn / as sysdba

SQL>alter user scott identified by tiger account unlock;

SQL>conn scott/tiger

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

ERROR:

ORA-01034: ORACLE not available

ORA-27101: shared memory realm does not exist

Linux Error: 2: No such file or directory

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

查看数据库相关的系统进程:

ps -ef | grep ora_

查看数据库的共享内存是否分配:

ipcs -sm

系统reboot后怎么启动数据库?

su - oracle

sqlplus / as sysdba

SQL>startup或者shutdown immediate

SQL>select status from v$instance; 查看实例状态，正常为open

SQL>conn scott/tiger