mysql> desc media;
+-------+--------------------------------------------------------------------------+-----+-------------+----------------+
| Field | Type                                                                     | Key | Default     | Extra          |
+-------+--------------------------------------------------------------------------+-----+-------------+----------------+
| mid   | tinyint(3) unsigned                                                      | PRI | NULL        | auto_increment |
| ext   | char(8)                                                                  |     |             |                |
| major | enum('application','audio','image','message','multipart','text','video') |     | application |                |
| minor | char(32)                                                                 |     |             |                |
+-------+--------------------------------------------------------------------------+-----+-------------+----------------+
4 rows in set (0.00 sec)

mysql> show index from media;
+-------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------------+
| Table | Non_unique | Key_name | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Index_type |
+-------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------------+
| media |          0 | PRIMARY  |            1 | mid         | A         |          25 |     NULL | NULL   | BTREE      |
| media |          0 | uk       |            1 | mid         | A         |        NULL |     NULL | NULL   | BTREE      |
| media |          0 | uk       |            2 | ext         | A         |          25 |     NULL | NULL   | BTREE      |
+-------+------------+----------+--------------+-------------+-----------+-------------+----------+--------+------------+
3 rows in set (0.00 sec)

mysql> select * from media order by major, minor;
+-----+-------+-------------+--------------------+
| mid | ext   | major       | minor              |
+-----+-------+-------------+--------------------+
|   6 | mml   | application | mathml+xml         |
|  10 | pdf   | application | pdf                |
|   7 | php   | application | x-httpd-php        |
|   8 | phps  | application | x-httpd-php-source |
|   9 | swf   | application | x-shockwave-flash  |
|   1 | xhtml | application | xhtml+xml          |
|   3 | xml   | application | xml                |
|   4 | xsl   | application | xml                |
|   5 | dtd   | application | xml-dtd            |
|   2 | xslt  | application | xslt+xml           |
|  21 | mp3   | audio       | mpeg               |
|  15 | gif   | image       | gif                |
|  12 | jpg   | image       | jpeg               |
|  13 | jpeg  | image       | jpeg               |
|  11 | png   | image       | png                |
|  14 | ico   | image       | x-icon             |
|  18 | css   | text        | css                |
|  16 | html  | text        | html               |
|  19 | js    | text        | javascript         |
|  17 | txt   | text        | plain              |
|  20 | sgml  | text        | sgml               |
|  22 | mpg   | video       | mpeg               |
|  23 | mpeg  | video       | mpeg               |
|  24 | mov   | video       | quicktime          |
|  25 | qt    | video       | quicktime          |
+-----+-------+-------------+--------------------+
25 rows in set (0.00 sec)