MULTINATIONAL collation is enabled at the user level via the COLLATION option of the CREATE USER or MODIFY USER statement. If a collation is not specified, the default is HOST. The standard sort ordering of the client system is EBCDIC for IBM clients and ASCII for all others.
You can override the default at the session level by issuing the SET SESSION COLLATION statement.
When MULTINATIONAL collation is in effect, the default collation sequence is determined by the collation setting installed at system start-up. Also see International Character Set Support, B035-1125.
Each international sort sequence is defined by program constants and no check is made to ensure that collation is compatible with the character set of the current session. The choice of sequence is controlled by your database administrator. The programmed character sequences cannot be changed.