Programmer Guide : Working with Unicode : Compatibility between Unicode and partial Unicode databases
  
Compatibility between Unicode and partial Unicode databases
If a database has been created in Unicode mode, it cannot be changed to partial Unicode mode, and vice versa. If you need to convert a partial Unicode database to a Unicode (or vice versa), you can use the solidDB® tools to export and reload your database.
If the database already exists in either mode and the database mode contradicts the value of the parameter, the server startup fails with the following error message in solerr.out.
Parameter General.InternalCharEncoding contradicts the existing database mode
See also
Converting partial Unicode databases to Unicode
Working with Unicode