def METHOD_NAME(db_dir, thumb_dir):
    '''
    Read archive database
    '''
    db_path = os.path.join(db_dir, 'archive.db')
    conn = sqlite3.connect(db_path)
    c = conn.cursor()
    c.execute('SELECT hash, format, type FROM blobs')
    data = c.fetchall()
    for item in data:
        blob = item[0]
        media_type = item[1]
        mime_type = item[2]
        thumb_path = os.path.join(thumb_dir, blob[:1], blob[1:2])
        thumb_path = os.path.join(thumb_path, blob) + '.jpeg'
        yield blob, media_type, mime_type, thumb_path