The identifier character set is the character set SQL uses for
    database object names, such as table names and column names.
    You can specify the identifier character set at the session and
    database level. The choice of identifier character set is limited
    to those character sets that include ASCII characters. This is
    necessary so that the object names for the Oracle Rdb system
    metadata, which is in ASCII, can be stored.

    You can specify the identifier character set for the database
    only when you create the database. You cannot alter the
    identifier character set of a database after creation.

    Following is a list of the character sets used for the identifier
    character set:

    o  ASCII

    o  AL24UTFFSS

    o  DEC_MCS

    o  DOS_LATIN1

    o  DOS_LATINUS

    o  DEVANAGARI

    o  DEC_SICGCC

    o  DEC_HANYU

    o  DEC_HANZI

    o  GB18030

    o  ISOLATINARABIC

    o  ISOLATINCYRILLIC

    o  ISOLATIN1

    o  ISOLATIN9

    o  ISOLATINGREEK

    o  ISOLATINHEBREW

    o  DEC_KANJI

    o  KATAKANA

    o  DEC_KOREAN

    o  SHIFT_JIS

    o  UTF8

    o  UNSPECIFIED

    o  TACTIS

    o  WIN_ARABIC

    o  WIN_GREEK

    o  WIN_CYRILLIC

    o  WIN_HEBREW

    When you compile SQL programs (either SQL module language or
    precompiled SQL), SQL uses the following to derive the identifier
    character set:

    o  The IDENTIFIER CHARACTER SET clause of the SQL module header
       or the DECLARE MODULE statement specifies the character set
       for parameters that are not qualified by a character set.

    o  In dynamic SQL, the SET IDENTIFIER CHARACTER SET statement
       specifies, at run time, the character set for parameters that
       are not qualified by a character set.

    o  The RDB$CHARACTER_SET logical name. However, the logical name
       is deprecated and will not be supported in a future release.

    SQL uses DEC_MCS as the identifier character set, unless you have
    set the dialect to MIA or specified an identifier character set
    at the session level. You can override any identifier character
    set by specifying another identifier character set when creating
    a database.