1 状态查询

    启动状态 SQL语句 结果
    nomount select status from v$instance; STARTED
    select open_mode from v$database; ERROR at line 1:
    ORA-01507: database not mounted
    mount select status from v$instance; MOUNTED
    select open_mode from v$database; MOUNTED
    open select status from v$instance; OPEN
    select open_mode from v$database; READ WRITE 或者 READ ONLY

    2 实验过程

    1. SQL> startup nomount;

    ORACLE instance started.

    Total System Global Area 125829120 bytes
    Fixed Size 1247684 bytes
    Variable Size 92276284 bytes
    Database Buffers 25165824 bytes
    Redo Buffers 7139328 bytes

    1. SQL> select status from v$instance;

    STATUS
    ——————
    STARTED

    1. SQL> select open_mode from v$database;
    2. select open_mode from v$database

    ERROR at line 1:
    ORA-01507: database not mounted

    1. SQL> alter database mount;

    Database altered.

    1. SQL> select status from v$instance;

    STATUS
    ——————
    MOUNTED

    1. SQL> select open_mode from v$database;

    OPEN_MODE
    —————
    MOUNTED

    1. SQL> alter database open;

    Database altered.

    1. SQL> select status from v$instance;

    STATUS
    ——————
    OPEN

    1. SQL> select open_mode from v$database;

    OPEN_MODE
    —————
    READ WRITE