The character data types should be encoded using Unicode.
On Derby, character data types are encoded using Unicode by
default so specifying this does not change the encoding.
On MySQL, this case object specifies the "utf8" character set. If
the collation is not specified then the "utf8_unicode_ci" collation
is used. See http://stackoverflow.com/questions/766809/ why this
slower collation is used instead the "utf8_general_ci" collation,
which is MySQL's default collation for the "utf8" character set.
On Oracle, this specifies that NCHAR is used for CharType and
NVARCHAR2 for VarcharType.
On PostgreSQL, this case object is ignored as the character set
encoding can only be specified when the database is created; using
it generates a runtime warning.