我的数据库中有很长的选择，有很多连接。问题在于计算 SUM：没有 sum，选择时间约为 3 秒，但使用 SUM 约为 15 秒。
是否可以优化我的选择以获得更短的选择时间？
这是我的代码：
SELECT
accomodation.id,
accomodation.aid,
accomodation.title_en,
accomodation.title_url_en,
accomodation.address,
accomodation.zip,
accomodation.stars,
accomodation.picture,
accomodation.valid_from,
accomodation.valid_to,
accomodation.latitude,
accomodation.longitude,
accomodation.city_id AS
accomodation_city_id,
db_cities.id AS city_id,
db_cities.title_en AS city,
db_cities.title_url AS city_url,
db_countries.title_en AS country_title,
db_countries.title_url_en AS country_url,
accomodation_type.class AS accomodation_type_class,
accomodation_review_value_total.value AS review_total,
MIN(accomodation_price.price) AS price_from,
accomodation_rooms.total_persons
FROM
(SELECT aid, MAX(info_date_add) AS max_info_date_add FROM accomodation GROUP BY aid) accomodation_max
INNER JOIN accomodation
ON
accomodation_max.aid = accomodation.aid AND
accomodation_max.max_info_date_add = accomodation.info_date_add
LEFT JOIN db_cities
ON (
db_cities.id = accomodation.city_id OR
(((acos(sin((db_cities.latitude*pi()/180)) * sin((accomodation.latitude*pi()/180)) + cos((db_cities.latitude*pi()/180)) * cos((accomodation.latitude*pi()/180)) * cos(((db_cities.longitude - accomodation.longitude)*pi()/180))))*180/pi())*60*1.1515*1.609344) < '20')
JOIN db_countries
ON db_countries.id = accomodation.country_id
LEFT JOIN accomodation_review_value_total
ON accomodation_review_value_total.accomodation_aid = accomodation.aid
LEFT JOIN accomodation_type_value
ON accomodation_type_value.accomodation_id = accomodation.id
LEFT JOIN accomodation_type
ON accomodation_type.id = accomodation_type_value.accomodation_type_id
JOIN accomodation_season
ON (
accomodation_season.accomodation_aid = accomodation.aid AND
( '2013-11-04' BETWEEN accomodation_season.start_date AND accomodation_season.end_date OR '2013-11-05' BETWEEN accomodation_season.start_date AND accomodation_season.end_date ) )
JOIN accomodation_price
ON
accomodation_price.accomodation_aid = accomodation.aid AND
accomodation_price.accomodation_price_type_id = '1' AND
accomodation_price.accomodation_price_cat_id = '1' AND
accomodation_price.price BETWEEN '20' AND '250' AND
accomodation_price.accomodation_season_id = accomodation_season.id
JOIN accomodation_theme_value
ON accomodation_theme_value.accomodation_id = accomodation.id
INNER JOIN
(SELECT
accomodation_id,
SUM(accomodation_rooms.rooms) AS total_rooms,
SUM(accomodation_rooms.beds * accomodation_rooms.rooms) AS total_persons
FROM accomodation_rooms
GROUP BY accomodation_id) accomodation_rooms
ON
accomodation_rooms.accomodation_id = accomodation.id AND
accomodation_rooms.total_persons >= '4'
WHERE
db_countries.title_url_en LIKE '%spain%' AND
db_cities.title_url LIKE '%barcelona%' AND
accomodation_type_value.accomodation_type_id IN (5,10) AND
total_rooms >= '2' AND
accomodation_theme_value.accomodation_theme_id IN (11,12,13) AND
accomodation.stars IN (3,4,5) AND
( accomodation_review_value_total.value >= '4.5' ) AND
db_cities.id = '2416'
GROUP BY accomodation.aid
ORDER BY
CASE
WHEN accomodation.valid_to>=NOW() AND accomodation.valid_from<=NOW() AND MIN(accomodation_price.price) IS NOT NULL THEN 0
WHEN NOW()>accomodation.valid_to AND accomodation.valid_to>'0000-00-00' AND MIN(accomodation_price.price) IS NOT NULL THEN 1
WHEN accomodation.valid_to>=NOW() AND accomodation.valid_from<=NOW() THEN 2
WHEN NOW()>accomodation.valid_to AND accomodation.valid_to>'0000-00-00' THEN 3
ELSE 4 END,
review_total DESC,
accomodation.title_en
LIMIT 10