A database consists of physical data storage characteristics,
    such as a root file and storage area specifications; metadata
    definitions, such as tables and domains; and user data.

    By default, a database contains a single schema and no catalogs.
    If you specify the multischema attribute when creating your
    database, you can group the data definitions within one or more
    schemas within one or more catalogs. See the CREATE DATABASE for
    information on how to create a multischema database.

    When you create a database, you name it by specifying a file
    name and an optional repository path name in the CREATE DATABASE
    statement. You can supply a complete file specification, a
    partial file specification, or use system-supplied default
    values. You must use ASCII alphanumeric characters for the
    database name.

    To perform operations on a database, the database name is
    referenced through an attachment to that database called an
    alias. When you first refer to a database in SQL, you must
    indicate the source of data definitions for the database and the
    location of database files by declaring an alias. You can declare
    an alias using one of three statements:

    o  ATTACH

    o  CONNECT

    o  DECLARE ALIAS

    Choose a statement based on the interface that you are using
    (interactive SQL, SQL module language, or precompiled SQL) and
    your purpose (declaring a new alias or overriding the association
    between an alias and a database name). More information about
    aliases appears in Aliases.

    There are two ways to identify the source of data definitions:

    o  With a file specification

    o  With a repository path name (if the repository is installed on
       the system)