def set_writeable(writeable_):
    """Sets whether the database is being written to disk, or just organized in
    memory.

    Args: 

        writeable_ (bool): when True, calling :meth:`acorn.database.record` will
          eventually result in an entry being saved to disk; otherwise, records are
          organized in memory, but the disk write is disabled.
    """
    global writeable
    writeable = writeable_
