DBLINK 9i 连接11G 错误信息ora-01017,ora-02063的解决方法

在oracle9i中建立一个dblink指向一个oracle11g的数据库，用户名、密码配置完毕以后测试，抛出这样的错误码：

ORA-01017: invalid username/password; logon denied
ORA-02063: preceding line from <link_name>

然后不知所措，到网上一搜，找到一段英文解释，如下：

Cause
The following Bug 6738104 was logged for this issue which was closed as not a bug saying the cause being introduction of password case sensitivity feature in 11g

When one creates a database link connection, a user name and password for the connection needs to be defined. When the database link is created, the password is case sensitive. Before a user can connect from a pre-release 11g database to a 11g release database and as the password case sensitivity is enabled by default, you must re-create the password for this database link using all uppercase letters.

The reason you need to re-create the password using all uppercase letters is so that it will match how Oracle Database stores database link passwords. Oracle Database always stores this type of password in uppercase letters, even if the password had originally been created using lower or mixed case letters. If case sensitivity is disabled, the user can enter the password using the case the password was created in.

Solution
++ As the password case sensitivity is enabled by default, create the database link to the 11g database as shown below :

我的理解是这样的：当9i连接11g时，会自动将密码转化为大写，所以，如果11g的数据库用户密码中，如果有小写字母，应该全部改成大写，然后再去用9i去连接，问题就解决了。