Specifies the name of a database and the source of the data
    definitions to be accessed by interactive SQL or by a program
    at run time. Makes the specified database part of the current
    database environment. The database environment is the set of all
    databases with unique aliases in the current connection.

    The ATTACH statement lets you add new databases at run time; it
    has no effect on the compile-time environment. To specify the
    compile-time environment, use the DECLARE ALIAS statement.

    You can name either a file or a repository path name to be used
    for the data definitions.

    If a transaction is currently active, SQL returns an
    informational message and does not attach the specified database
    environment to the connection.

    If a database is currently attached and you attach to another
    database without using an alias, SQL detaches the current
    database environment and attaches to the specified one in its
    place.