Syntax: open database-name [huge|long|short]

    The OPEN command opens an alias database after first closing
    any currently opened database. If the database to be opened
    already exists, then DB will automatically determine whether
    or not the database is a "huge" (stores 80/1024 character long
    alias names/values), or "long" (stores 80/132 character long
    alias names/values) or "short" (stores 32/80 character long alias
    names/values). If the database does not already exist, then it
    will be created. If the SHORT, LONG, or HUGE keyword is specified
    after the database file name, then the database created will be
    of that type. If no keyword is specified, the created database
    will be a long database.

    When DB is first invoked, the personal alias database pointed
    at by the logical PMDF_PERSONAL_ALIAS_DATABASE is automatically
    opened. If it doesn't exist, a long database is automatically
    created. Note that because of this, if you want a huge or short
    database instead of a long one, you must create a database file
    of the desired size either (e.g. for a huge database) using "pmdf
    crdb/huge", or by using the DB "open other-file huge" command
    then renaming other-file to the PMDF_PERSONAL_ALIAS_DATABASE
    name.