title: Optimize MySQL Query
body: <p>I have a mysql query taking 13 seconds to execute is there any way to reduce the execution time here is the explain </p>
  
  <pre><code>EXPLAIN
  SELECT SQL_CALC_FOUND_ROWS st.store_id as st_id, `st`.`store_id`
  FROM `store` AS `st`
  LEFT JOIN `coupon` AS `cp` ON st.store_id = cp.store_id
  LEFT JOIN `deal` AS `dl` ON st.store_id = dl.store_id
  LEFT JOIN `store_category_relations` AS `scr` ON st.store_id = scr.store_id
  GROUP BY `st`.`store_id`;
  
  +----+-------------+-------+-------+-----------------------+-----------------------+---------+---------------------+------+-------------+
  | id | select_type | table | type  | possible_keys         | key                   | key_len | ref                 | rows | Extra       |
  +----+-------------+-------+-------+-----------------------+-----------------------+---------+---------------------+------+-------------+
  |  1 | SIMPLE      | st    | index | NULL                  | PRIMARY               | 4       | NULL                |    1 | Using index |
  |  1 | SIMPLE      | cp    | ref   | store_id              | store_id              | 4       | sonicqa.st.store_id |    5 | Using index |
  |  1 | SIMPLE      | dl    | ref   | idx_deal_fid_store_id | idx_deal_fid_store_id | 4       | sonicqa.st.store_id |  287 | Using index |
  |  1 | SIMPLE      | scr   | ref   | store_id              | store_id              | 4       | sonicqa.st.store_id |    2 | Using index |
  +----+-------------+-------+-------+-----------------------+-----------------------+---------+---------------------+------+-------------+
  4 rows in set (0.00 sec)
  </code></pre>