问题现象：
alter user scott account unlock;
ERROR at line 1:
ORA-01034: ORACLE not available
Process ID: 0
Session ID: 0 Serial number: 0
[oracle@rhel ~]$ echo $ORACLE_SID xxxx [oracle@rhel ~]$ sqlplus / as sysdba SQL*Plus: Release 11.2.0.4.0 Production on Tue Sep 12 14:58:57 2017 Copyright (c) 1982, 2013, Oracle. All rights reserved. Connected to an idle instance. SQL> select userenv(‘language‘) from udal; select userenv(‘language‘) from udal * ERROR at line 1: ORA-01034: ORACLE not available Process ID: 0 Session ID: 0 Serial number: 0
问题解决：
确认当前实例对不
export ORACLE_SID=xxxx --设置
echo $ORACLE_SID=xxxx --查看
查看监听状态
lsnrctl status
sqlplus sys/123123@sznfpt as sysdba #明确登录的用户及实例，就OK了
[oracle@rhel ~]$ sqlplus sys/123123@sznfpt as sysdba SQL*Plus: Release 11.2.0.4.0 Production on Tue Sep 12 15:02:47 2017 Copyright (c) 1982, 2013, Oracle. All rights reserved. Connected to: Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production With the Partitioning, OLAP, Data Mining and Real Application Testing options SQL> SQL> SQL> alter user scott account unlock; User altered. SQL> SQL> SQL> alter user scott identified by 123123; User altered. SQL>
ORA-01034: ORACLE not available解决
原文：http://www.cnblogs.com/xiaochina/p/7510239.html