【oracle】oracle常用命令汇总

查看数据库状态（普通用户登录要保证数据库是open状态）

SQL> select status from v$instance;

 创建用户（新用户需要授予连接权限才能连上数据库）

SQL> create user user1 identified by redhat;
SQL> conn user1/redhat 
ERROR:
ORA-01045: user USER1 lacks CREATE SESSION privilege; logon denied
Warning: You are no longer connected to ORACLE.
SQL> show user
USER is ""
SQL> conn / as sysdba
Connected.
SQL> grant connect to user1;
SQL> conn user1/redhat;
Connected.

删除用户

SQL> drop user user1 ;

查看系统拥有哪些用户

SQL> select * from all_users;

 执行sql文件（PATH表示文件的路径）

SQL> @PATH/filename.sql

 测试sql语句执行时间

SQL>set timing on ;

 查看当前数据库名

SQL> select name from v$database;

 查看侦听状态/关闭侦听/开启侦听

[grid@rac01 ~]$ lsnrctl status
[grid@rac01 ~]$ lsnrctl stop
[grid@rac01 ~]$ lsnrctl start

 关闭数据库

SQL> shutdown immediate;

 开启数据库

SQL> startup

 查看当前用户角色

select * from user_role_privs;

 查看数据文件

select * from dba_data_files;

 查看数据库是否为归档模式

SQL> select name,log_mode from v$database;
SQL> archive log list;
SQL> select archiver from v$instance;

 开启数据库的归档模式（只能在mount状态开启）

SQL> alter database archivelog;
alter database archivelog
*
ERROR at line 1:
ORA-01126: database must be mounted in this instance and not open in any
instance

SQL> shutdown immediate;
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> 
SQL> startup mount
ORACLE instance started.

Total System Global Area  784998400 bytes
Fixed Size		    2257352 bytes
Variable Size		  541068856 bytes
Database Buffers	  239075328 bytes
Redo Buffers		    2596864 bytes
Database mounted.
SQL> 
SQL> alter database archivelog;

Database altered.

SQL> alter database open;

Database altered.

SQL> alter system archive log start;

System altered.

 关闭归档（同样要在mount状态下操作）

SQL> alter database noarchivelog;

-------------------------------------------------表空间-------------------------------

查看当前存在的表空间

select * from v$tablespace;

 查看表空间使用情况

SQL> select tablespace_name,sum(bytes)/1024/1024 from dba_data_files group by tablespace_name; -- 单位是M

 查看用户默认表空间

SQL> select username,default_tablespace from dba_users;

 创建表空间（数据文件名一定是单引号引起来）

SQL> create tablespace test_tbsp datafile '/home/oracle/oradata/test_tbsp.dbf' size 100M;

修改用户表空间

SQL> alter user user1 default tablespace test_tbsp;

 查看表空间是否自动扩展

SQL> select file_name,autoextensible,increment_by from dba_data_files where tablespace_name='TEST_TBSP';

 表空间开启自动扩展

SQL> alter database datafile '/home/oracle/oradata/test_tbsp.dbf' autoextend on;

 表空间关闭自动扩展

SQL> alter database datafile '/home/oracle/oradata/test_tbsp.dbf' autoextend off;