1  –  alias.name-of-catalog

    Specifies a name for the attachment to the database. Always
    qualify the catalog name with an alias if your program or
    interactive SQL statements refer to more than one database.
    Separate the name of the catalog from the alias with a period,
    and enclose the qualified name in double quotation marks.

    You must issue a SET QUOTING RULES statement before you can
    qualify a catalog name with an alias.

2  –  CATALOG

    Syntax options:

    CASCADE | RESTRICT

    Performs a restricted delete by default. If you prefer to delete
    all definitions contained in the catalog, you can specify the
    DROP CATALOG CASCADE statement.

3  –  catalog-name

    Specifies the module catalog name.

4  –  IF_EXISTS

    Prevents SQL command language from displaying error messages if
    the referenced object does not exist in the database.