在DBA的日常工作中，经常遇到为Oracle用户解锁的操作；这篇文章给出在命令行下进行Oracle用户解锁的操作方法，通过几条简单的解锁语句就能完成此项工作。下面是具体的过程：
默认的scott用户是被锁定的，先解锁就能登陆上了。 使用下面的语句解锁scott:
alter user scott account unlock;
解锁之后可能会要求你该密码：
alter user scott identified by tiger;
再登陆：
sqlplus scott/tiger
就能登陆了
Oracle锁定和解锁用户的命令
sql> conn /as sysdba
已连接。
//scott 用户在没有设定tieger默认密码时，登陆不上
sql> alter user test account lock;
用户已更改。
-------test用户登陆数据库，失败了。
C:>sqlplus test/test
ERROR:
ORA-28000: the account is locked
sql> conn /as sysdba
sql> alter user test account unlock;
==============
查看数据库名
sql> select name from v$database;
NAME
---------
ORCL
sql> desc v$database;
名称 是否为空? 类型
----------------------------------------- -------- ----------------------------
DBID NUMBER
NAME VARCHAR2(9)
CREATED DATE
RESETLOGS_CHANGE# NUMBER
RESETLOGS_TIME DATE
PRIOR_RESETLOGS_CHANGE# NUMBER
PRIOR_RESETLOGS_TIME DATE
LOG_MODE VARCHAR2(12)
CHECKPOINT_CHANGE# NUMBER
ARCHIVE_CHANGE# NUMBER
CONTROLFILE_TYPE VARCHAR2(7)
CONTROLFILE_CREATED DATE
CONTROLFILE_SEQUENCE# NUMBER
CONTROLFILE_CHANGE# NUMBER
CONTROLFILE_TIME DATE
OPEN_RESETLOGS VARCHAR2(11)
VERSION_TIME DATE
OPEN_MODE VARCHAR2(10)
PROTECTION_MODE VARCHAR2(20)
PROTECTION_LEVEL VARCHAR2(20)
REMOTE_ARCHIVE VARCHAR2(8)
ACTIVATION# NUMBER
SWITCHOVER# NUMBER
DATABASE_ROLE VARCHAR2(16)
ARCHIVELOG_CHANGE# NUMBER
ARCHIVELOG_COMPRESSION VARCHAR2(8)
SWITCHOVER_STATUS VARCHAR2(20)
DATAGUARD_BROKER VARCHAR2(8)
GUARD_STATUS VARCHAR2(7)
SUPPLEMENTAL_LOG_DATA_MIN VARCHAR2(8)
SUPPLEMENTAL_LOG_DATA_PK VARCHAR2(3)
SUPPLEMENTAL_LOG_DATA_UI VARCHAR2(3)
FORCE_LOGGING VARCHAR2(3)
PLATFORM_ID NUMBER
PLATFORM_NAME VARCHAR2(101)
RECOVERY_TARGET_INCARNATION# NUMBER
LAST_OPEN_INCARNATION# NUMBER
CURRENT_SCN NUMBER
FLASHBACK_ON VARCHAR2(18)
SUPPLEMENTAL_LOG_DATA_FK VARCHAR2(3)
SUPPLEMENTAL_LOG_DATA_ALL VARCHAR2(3)
DB_UNIQUE_NAME VARCHAR2(30)
STANDBY_BECAME_PRIMARY_SCN NUMBER
FS_FAILOVER_STATUS VARCHAR2(21)
FS_FAILOVER_CURRENT_TARGET VARCHAR2(30)
FS_FAILOVER_THRESHOLD NUMBER
FS_FAILOVER_OBSERVER_PRESENT VARCHAR2(7)
FS_FAILOVER_OBSERVER_HOST VARCHAR2(512)
---------------------------------------
查看实例名
sql> select instance_name from v$instance;
INSTANCE_NAME
----------------
orcl
sql> desc v$instance; 名称 是否为空? 类型 ----------------------------------------- -------- -------------- INSTANCE_NUMBER NUMBER INSTANCE_NAME VARCHAR2(16) HOST_NAME VARCHAR2(64) VERSION VARCHAR2(17) STARTUP_TIME DATE STATUS VARCHAR2(12) PARALLEL VARCHAR2(3) THREAD# NUMBER ARCHIVER VARCHAR2(7) LOG_SWITCH_WAIT VARCHAR2(15) LOGINS VARCHAR2(10) SHUTDOWN_PENDING VARCHAR2(3) DATABASE_STATUS VARCHAR2(17) INSTANCE_ROLE VARCHAR2(18) ACTIVE_STATE VARCHAR2(9) BLOCKED VARCHAR2(3)
