Up to and including version 7.6, you could choose ASCII as character set for SAP MaxDB (8 bit ASCII character set ISO 8859/1.2, which contains 256 characters).
Caution
Starting with version 7.7, the catalog data of all SAP MaxDB databases are stored in Unicode. Therefore, databases of versions up to and including 7.6. the catalog data of which are not stored in Unicode need to be migrated before you can upgrade them to version 7.7.
For more information about migrating your database, see your installation and upgrade documentation.
SQL Reference Manual, Code Attribute