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一、查看实例名、表等

[oracle@shoubashou.com ~]$ sqlplus scott/tiger@orcl

SQL> show user;

USER is "SCOTT"

SQL> select * from tab;

TNAME                          TABTYPE  CLUSTERID

------------------------------ ------- ----------

BONUS                          TABLE   

DEPT                           TABLE   

EMP                            TABLE   

SALGRADE                       TABLE   

SQL> conn sys/oracle@orcl as sysdba

Connected to Oracle Database 11g Enterprise Edition Release 11.2.0.3.0 

Connected as sys@orcl AS SYSDBA

SQL> select name from v$database;

NAME

---------

ORCL

SQL> select * from global_name; #数据库全局名称

GLOBAL_NAME

--------------------------------------------------------------------------------

ORCL

SQL> show parameter global_names;

NAME                                 TYPE        VALUE

------------------------------------ ----------- ------------------------------

global_names                         boolean     FALSE

SQL> select status from v$instance;

STATUS  #  手把手

------------

OPEN
 

二、启动几个阶段状态实验

1. nomount

SQL> startup nomount

ORACLE instance started.

Total System Global Area 1286066176 bytes

Fixed Size                  2228024 bytes

Variable Size             352321736 bytes

Database Buffers          922746880 bytes

Redo Buffers                8769536 bytes

SQL> select status from v$instance;

STATUS

------------

STARTED

SQL> select open_mode from v$database;

select open_mode from v$database

                      *

ERROR at line 1:

ORA-01507: database not mounted

2. mount

SQL> alter database mount;

Database altered.

SQL> select status from v$instance;

STATUS

------------

MOUNTED

SQL> select open_mode from v$database;

OPEN_MODE

--------------------

MOUNTED

3.open

SQL> alter database open ;

Database altered.

SQL> select status from v$instance;

STATUS

------------

OPEN

SQL> select open_mode from v$database;

OPEN_MODE

--------------------

READ WRITE

4. close

SQL> alter database close;

Database altered.

SQL> select status from v$instance;

STATUS

------------

MOUNTED

SQL> select open_mode from v$database;

OPEN_MODE

--------------------

MOUNTED

# 数据库open_mode的read only和read write，改变了需要重新启动数据库。

原文转自：https://www.shoubashou.com/db/oracle/95.html