Oracle RDBMS: Database Link fails with ORA-1017 & ORA-2063

If you try to create a database link between a 10g and a 11g instance. There is a good chance that you might get the following error:

ORA-01017: invalid username/password; logon denied

ORA-02063: preceding line from (database_link_name)

The reason is from Oracle 11g Release 1 the passwords are case-sensitive by default.

Example:

My target database is 11g - named TIGER

Create public database link TIGER connect to dbadmin identified by dbadmin1

using 'TIGER';

select * from v$instance@TIGER;

ORA-01017: invalid username/password; logon denied

ORA-02063: preceding line from TIGER

Solution:

1) On the originating 10g database server, drop and recreate the public database link using double quotes around the password (IDENTIFIED BY clause) for the user account on the 11g Database

Drop public database link TIGER;

Create public database link TIGER connect to dbadmin identified by "dbadmin1"

using 'TIGER';

OR

2) Use the 'SEC_CASE_SENSITIVE_LOGON' initialization parameter on the target (11g Database) to disable password case sensitivity in the destination database.

Dynamic change:

ALTER SYSTEM SET SEC_CASE_SENSITIVE_LOGON = FALSE SCOPE=BOTH;

PFILE change:

SEC_CASE_SENSITIVE_LOGON = FALSE

Reference: Database Link from 10g to 11g fails with ORA-1017 & ORA-2063 [ID 473716.1]