1  –  DATE

    ON | OFF

    Specifies the default interpretation for columns with the DATE
    data type, and the data type of the CURRENT_TIMESTAMP function.

    The DATE and CURRENT_TIMESTAMP data types, can be either VMS
    ADT or ANSI. By default, both data types are interpreted as DATE
    VMS. The VMS format contains YEAR TO SECOND fields, just as a
    TIMESTAMP does.

    You can change DATE and CURRENT_TIMESTAMP to ANSI format with
    the SET DEFAULT DATE FORMAT statement, the precompiler DEFAULT
    DATE FORMAT clause in a DECLARE MODULE statement embedded in a
    program, or the module language DEFAULT DATE FORMAT clause in a
    module file. The ANSI format DATE contains only the YEAR TO DAY
    fields.

    You must use the SET DEFAULT DATE FORMAT statement before
    creating domains or tables. You cannot use this statement to
    modify the data type once you have created a column or table.

2  –  IDENTIFIERS

    ON | OFF

    Specifies whether or not SQL checks statements that use reserved
    words as identifiers. If you specify SET ANSI IDENTIFIERS ON, SQL
    checks statements for reserved words from the ANSI/ISO standard.
    You must enclose reserved words in double quotation marks to
    supply them as identifiers in SQL statements. If you do not,
    SQL issues an informational message after such statements when
    you enable reserved-word checking. For a list of the reserved
    words deprecated as identifiers, see the Oracle Rdb SQL Reference
    Manual.

    When you specify SET ANSI IDENTIFIERS OFF, SQL does not check
    identifiers. By default, SQL does not check identifiers.

3  –  QUOTING

    ON | OFF

    Allows you to use double quotation marks to delimit the alias
    and catalog name pair in subsequent statements. By default,
    SQL syntax allows only single quotation marks. To comply with
    ANSI/ISO SQL standard naming conventions, ANSI QUOTING must be
    on. You must set ANSI QUOTING on to use multischema database
    naming.