Collations control character ordering. The results of character comparisons depends on the collation sequence of the character set in use.
You can set the default collation to a sequence that is compatible with the character set for your session. Use the HELP SESSION SQL statement to determine the collation setting for your current session.
The availability of diacritical or Japanese character sets, and your default collation sequence are under the control of your database administrator.
To ensure that sorting and comparison of character data are identical with the same operations performed by the client, users on a Japanese language site should set collation to CHARSET_COLL.