mysql - multi-column index and ORDER BY

Question

I have a mysql database with 7 million rows hosted on an aws rds micro instance.

I am doing this sort of queries:

SELECT
  `id`, `address`, `property_type`, `rooms`,
  `published`, `size`, `net_rent`, `gross_rent`,
  `purchase_price`, `original_id`
FROM (`properties`)
WHERE
  `postcode` IN ('1000', '1001', '1002', '1003',
                 '1004', '1005', '1006', '1007',
                 '1010', '1011', '1012', '1014',
                 '1015', '1017', '1018', '1019')
  AND `published` < '2013-01-09'
  AND `property_type` IN ('Apartment', 'Apartment with terrace',
                          'Attic', 'Attic flat / penthouse',
                          'Loft', 'Maisonette', 'Studio')
  AND `sale_or_rent` = 'rent'
LIMIT 50

And thus I created an index like that:

| properties |          1 | listing       |            1 | postcode      | A         |       25091 |     NULL | NULL   | YES  | BTREE      |         |               |
| properties |          1 | listing       |            2 | published     | A         |     2333545 |     NULL | NULL   | YES  | BTREE      |         |               |
| properties |          1 | listing       |            3 | property_type | A         |     3500318 |     NULL | NULL   | YES  | BTREE      |         |               |
| properties |          1 | listing       |            4 | sale_or_rent  | A         |     3500318 |     NULL | NULL   | YES  | BTREE      |         |               |

Everything is fine so far. The problems arrise when I try to add ORDER BY published DESC (30"+ for one query).

Is there anyway to have an efficient ORDER BY published DESC knowing that I also need published to be in a WHERE clause?

Answer 1

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