Example 1: Setting the default, identifier, and literal character
    sets of an interactive session

    SQL> show character sets;
    Default character set is DEC_MCS
    National character set is DEC_MCS
    Identifier character set is DEC_MCS
    Literal character set is DEC_MCS
    Display character set is UNSPECIFIED
    SQL> --
    SQL> set names 'DEC_KANJI';
    SQL> show character sets;
    Default character set is DEC_KANJI
    National character set is DEC_MCS
    Identifier character set is DEC_KANJI
    Literal character set is DEC_KANJI
    Display character set is UNSPECIFIED
    SQL> --
    SQL> -- Specifying a different default character set
    SQL> --
    SQL> set default character set 'DEC_KOREAN';
    SQL> show character sets;
    Default character set is DEC_KOREAN
    National character set is DEC_MCS
    Identifier character set is DEC_KANJI
    Literal character set is DEC_KANJI
    Display character set is UNSPECIFIED
    SQL>