在11g 以前的版本中用户名的密码对大小写是不敏感的

10G:

[oracle@asm ~]$ sqlplus paul/paul

SQL*Plus: Release 10.2.0.1.0 - Production on Tue Jul 22 16:19:01 2008

Connected to:
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options

SQL>

[oracle@asm ~]$ sqlplus paul/PAUL

SQL*Plus: Release 10.2.0.1.0 - Production on Tue Jul 22 16:19:13 2008

Connected to:
Oracle Database 10g Enterprise Edition Release 10.2.0.1.0 - Production
With the Partitioning, OLAP and Data Mining options

SQL>

11g:

[oracle@asm11g ~]$ sqlplus paul/paul

SQL*Plus: Release 11.1.0.6.0 - Production on Mon Jul 21 04:50:46 2008

Connected to:
Oracle Database 11g Enterprise Edition Release 11.1.0.6.0 - Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options

SQL> exit
Disconnected from Oracle Database 11g Enterprise Edition Release 11.1.0.6.0 - Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options
[oracle@asm11g ~]$ sqlplus paul/PAUL

SQL*Plus: Release 11.1.0.6.0 - Production on Mon Jul 21 04:50:49 2008

ERROR:
ORA-01017: invalid username/password; logon denied

Enter user-name:

这个新特性是在dbca创建数据库默认就会选上的

keep the enhanced 11g default security setting (recommended)

可以通过 SEC_CASE_SENSITIVE_LOGON 初始化参数来关闭这个特性

默认值为true

SQL> show parameter sec_case_sensitive_logon

NAME TYPE
------------------------------------ ----------------------
VALUE
------------------------------
sec_case_sensitive_logon boolean
TRUE

关掉这个参数对大小写就不敏感了

SQL> ALTER SYSTEM SET SEC_CASE_SENSITIVE_LOGON = FALSE;

System altered.

SQL> show parameter sec_case_sensitive_logon

NAME TYPE
------------------------------------ ----------------------
VALUE
------------------------------
sec_case_sensitive_logon boolean
FALSE

[oracle@asm11g ~]$ sqlplus paul/PAUL

SQL*Plus: Release 11.1.0.6.0 - Production on Mon Jul 21 04:59:12 2008

Connected to:
Oracle Database 11g Enterprise Edition Release 11.1.0.6.0 - Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options

SQL>

oracle 11g username password 增强对大小写敏感