控制器
@from = params[:from] ? 4.hours.since(Time.zone.parse(params[:from])) : today_start_time
@to = params[:to] ? 4.hours.since(Time.zone.parse(params[:to])) : @from
@franchise = current_user_accessible_franchises_filtered
@orders_type = Restaurant::DELIVERY_TYPES.detect { |t| t == params[:orders_type]} || Restaurant::DELIVERY_TYPES.first
@limit = (params[:limit] || 250).to_i
@to = 48.hours.since(@to) if @to == @from && @from == today_start_time
start_time = @from.utc.strftime('%Y-%m-%d %H:%M')
end_time = 24.hours.since(@to).utc.strftime('%Y-%m-%d %H:%M')
@orders = Order
.includes(:address, :franchise, :customer, :ordered_items, :rests, :driver)
.where(
"((orders.created_at >= ? AND orders.created_at <= ?) OR (orders.delivery_target >= ? AND orders.delivery_target <= ?)) AND orders.franchise_id in (?) AND orders.delivery_type = ?",
start_time, end_time, start_time, end_time, @franchise, @orders_type
)
.order("orders.status desc, orders.id desc")
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（23732.8ms）SELECT COUNT（DISTINCT
orders。id）FROMordersLEFT 外联addressesaddresses。id=orders。address_idLEFT OUTER JOINfranchisesONfranchises。id=orders。franchise_idLEFT OUTER JOINcustomersONcustomers。id=orders。customer_idLEFT OUTER JOINordered_itemsordered_items。order_id=orders。id左 外部加入ordered_itemsordered_items_orders_join开启ordered_items_orders_join。order_id=orders。idLEFT OUTER JOINrestaurantsrestaurants。id=ordered_items_orders_join。restaurant_idLEFT OUTER JOINdrivers在drivers。id=orders。driver_idWHERE（（（orders.created_at＆gt; = ＆＃39; 2015-03-01 10:00＆＃39; AND orders.created_at＆lt; =＆＃39; 2015-03-04 10：00＆＃39;）或 （orders.delivery_target＆gt; =＆＃39; 2015-03-01 10：00＆＃39; AND orders.delivery_target＆lt; =＆＃39; 2015-03-04 10:00＆＃39;））AND orders.franchise_id 在 （3,31,4,22,37,2,36,17,34,30,19,20,21,18,27,13,25,16,35,24,32,33,1,12,28 ，23,14,26,29,8,11） AND orders.delivery_type =＆＃39;先生。送餐服务＆＃39;）
EXPLAIN EXTENDED
mysql> EXPLAIN EXTENDED
SELECT DISTINCT `orders`.id
FROM `orders`
LEFT OUTER JOIN `addresses` ON `addresses`.`id` = `orders`.`address_id`
LEFT OUTER JOIN `franchises` ON `franchises`.`id` = `orders`.`franchise_id`
LEFT OUTER JOIN `customers` ON `customers`.`id` = `orders`.`customer_id`
LEFT OUTER JOIN `ordered_items` ON `ordered_items`.`order_id` = `orders`.`id`
LEFT OUTER JOIN `ordered_items` `ordered_items_orders_join`
ON `ordered_items_orders_join`.`order_id` = `orders`.`id`
LEFT OUTER JOIN `restaurants` ON `restaurants`.`id` = `ordered_items_orders_join`.`restaurant_id`
LEFT OUTER JOIN `drivers` ON `drivers`.`id` = `orders`.`driver_id`
WHERE ( ( (orders.created_at >= '2015-02-01 10:00'
AND orders.created_at <= '2015-02-04 10:00')
OR (orders.delivery_target >= '2015-02-01 10:00'
AND orders.delivery_target <= '2015-02-04 10:00') )
AND orders.franchise_id in (3,31,4,22,37,2,36,17,34,30,
19,20,21,18,27,13,25,16,35,24,32,33,1,12,28,23,14,26,29, 8,11 )
AND orders.delivery_type = 'Mr. Delivery Restaurant'
)
ORDER BY orders.status desc,
orders.id desc
LIMIT 250;
+----+-------------+---------------------------+--------+------------------------------------------------------------------------------------------------------------------------------+---------------------------------+---------+---------------------------------------------------------+--------+----------+----------------------------------------------+
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | filtered | Extra |
+----+-------------+---------------------------+--------+------------------------------------------------------------------------------------------------------------------------------+---------------------------------+---------+---------------------------------------------------------+--------+----------+----------------------------------------------+
| 1 | SIMPLE | orders | ref | index_orders_on_created_at,index_orders_on_delivery_target,index_orders_on_franchise_id,index_orders_on_delivery_type,my_idx | index_orders_on_delivery_type | 77 | const | 549769 | 100.00 | Using where; Using temporary; Using filesort |
| 1 | SIMPLE | addresses | eq_ref | PRIMARY | PRIMARY | 4 | mrd_staging_new.orders.address_id | 1 | 100.00 | Using index; Distinct |
| 1 | SIMPLE | franchises | eq_ref | PRIMARY | PRIMARY | 4 | mrd_staging_new.orders.franchise_id | 1 | 100.00 | Using index; Distinct |
| 1 | SIMPLE | customers | eq_ref | PRIMARY | PRIMARY | 4 | mrd_staging_new.orders.customer_id | 1 | 100.00 | Using index; Distinct |
| 1 | SIMPLE | ordered_items | ref | index_ordered_items_on_order_id | index_ordered_items_on_order_id | 5 | mrd_staging_new.orders.id | 2 | 100.00 | Using index; Distinct |
| 1 | SIMPLE | ordered_items_orders_join | ref | index_ordered_items_on_order_id | index_ordered_items_on_order_id | 5 | mrd_staging_new.orders.id | 2 | 100.00 | Distinct |
| 1 | SIMPLE | restaurants | eq_ref | PRIMARY | PRIMARY | 4 | mrd_staging_new.ordered_items_orders_join.restaurant_id | 1 | 100.00 | Using index; Distinct |
| 1 | SIMPLE | drivers | eq_ref | PRIMARY | PRIMARY | 4 | mrd_staging_new.orders.driver_id | 1 | 100.00 | Using index; Distinct |
+----+-------------+---------------------------+--------+------------------------------------------------------------------------------------------------------------------------------+---------------------------------+---------+---------------------------------------------------------+--------+----------+----------------------------------------------+
8 rows in set, 1 warning (0.00 sec)
指数
| Table | Non_unique | Key_name | Seq_in_index | Column_name | Collation | Cardinality | Sub_part | Packed | Null | Index_type | Comment | Index_comment |
+--------+------------+---------------------------------------+--------------+-----------------------+-----------+-------------+----------+--------+------+------------+---------+---------------+
| orders | 0 | PRIMARY | 1 | id | A | 935943 | NULL | NULL | | BTREE | | |
| orders | 1 | index_orders_on_delivered_at | 1 | delivered_at | A | 935943 | NULL | NULL | YES | BTREE | | |
| orders | 1 | index_orders_on_updated_at | 1 | updated_at | A | 935943 | NULL | NULL | YES | BTREE | | |
| orders | 1 | index_orders_on_created_at | 1 | created_at | A | 935943 | NULL | NULL | YES | BTREE | | |
| orders | 1 | index_orders_on_pickup_at | 1 | pickup_at | A | 935943 | NULL | NULL | YES | BTREE | | |
| orders | 1 | index_orders_on_coupon_id | 1 | coupon_id | A | 14856 | NULL | NULL | YES | BTREE | | |
| orders | 1 | index_orders_on_driver_id | 1 | driver_id | A | 4159 | NULL | NULL | YES | BTREE | | |
| orders | 1 | index_orders_on_delivery_target | 1 | delivery_target | A | 935943 | NULL | NULL | YES | BTREE | | |
| orders | 1 | index_orders_on_franchise_id | 1 | franchise_id | A | 48 | NULL | NULL | YES | BTREE | | |
| orders | 1 | idx_for_customers_report | 1 | customer_id | A | 935943 | NULL | NULL | YES | BTREE | | |
| orders | 1 | idx_for_customers_report | 2 | delivered_at | A | 935943 | NULL | NULL | YES | BTREE | | |
| orders | 1 | idx_for_customers_report | 3 | created_at | A | 935943 | NULL | NULL | YES | BTREE | | |
| orders | 1 | idx_for_customers_report | 4 | status | A | 935943 | NULL | NULL | | BTREE | | |
| orders | 1 | idx_for_customers_report | 5 | franchise_id | A | 935943 | NULL | NULL | YES | BTREE | | |
| orders | 1 | orders_fetch_index_for_revenue_report | 1 | id | A | 935943 | NULL | NULL | | BTREE | | |
| orders | 1 | orders_fetch_index_for_revenue_report | 2 | created_at | A | 935943 | NULL | NULL | YES | BTREE | | |
| orders | 1 | orders_fetch_index_for_revenue_report | 3 | delivered_at | A | 935943 | NULL | NULL | YES | BTREE | | |
| orders | 1 | orders_fetch_index_for_revenue_report | 4 | status | A | 935943 | NULL | NULL | | BTREE | | |
| orders | 1 | orders_fetch_index_for_revenue_report | 5 | franchise_id | A | 935943 | NULL | NULL | YES | BTREE | | |
| orders | 1 | orders_fetch_index_for_revenue_report | 6 | customer_id | A | 935943 | NULL | NULL | YES | BTREE | | |
| orders | 1 | orders_fetch_index_for_revenue_report | 7 | address_id | A | 935943 | NULL | NULL | YES | BTREE | | |
| orders | 1 | index_orders_on_address_id | 1 | address_id | A | 935943 | NULL | NULL | YES | BTREE | | |
| orders | 1 | index_orders_on_customer_id | 1 | customer_id | A | 935943 | NULL | NULL | YES | BTREE | | |
| orders | 1 | index_orders_on_delivery_type | 1 | delivery_type | A | 4 | NULL | NULL | | BTREE | | |
| orders | 1 | index_orders_on_status | 1 | status | A | 8 | NULL | NULL | | BTREE | | |
| orders | 1 | index_orders_on_should_pay_restaurant | 1 | should_pay_restaurant | A | 4 | NULL | NULL | YES | BTREE | | |
| orders | 1 | my_idx | 1 | created_at | A | 935943 | NULL | NULL | YES | BTREE | | |
| orders | 1 | my_idx | 2 | delivery_target | A | 935943 | NULL | NULL | YES | BTREE | | |
| orders | 1 | my_idx | 3 | franchise_id | A | 935943 | NULL | NULL | YES | BTREE | | |
| orders | 1 | my_idx | 4 | delivery_type | A | 935943 | NULL | NULL | | BTREE | | |
| orders | 1 | my_idx | 5 | status | A | 935943 | NULL | NULL | | BTREE | | |
| orders | 1 | my_idx | 6 | id | A | 935943 | NULL | NULL | | BTREE | | |
总数量
mysql> select count(*) from orders;
+----------+
| count(*) |
+----------+
| 965520 |
+----------+
1 row in set (0.32 sec)
我尝试添加综合索引
create index my_idx on orders(created_at, delivery_target, franchise_id, delivery_type);
甚至
create index my_idx on orders(created_at, delivery_target, franchise_id, delivery_type, status, id);
但没有成功。
有什么想法吗？
答案 0 :(得分：1)
INDEX(delivery_type, -- because it is "= constant"
franchise_id) -- the only other viable column
为隐藏在OR中的任何列编制索引实际上是徒劳的。
我在执行ORDER BY status时对您的DISTINCT id提出质疑，但未提及status。
可能能够通过将OR变为UNION
( SELECT orders.status, orders.id
FROM ...
JOIN ...
WHERE orders.created_at ...
AND ...
ORDER BY ...
LIMIT 250
)
UNION DISTINCT
( SELECT orders.status, orders.id
FROM ...
JOIN ...
WHERE orders.delivery_target ... -- note difference
AND ...
ORDER BY ...
LIMIT 250
)
ORDER BY status DESC, id DESC -- yes, again
LIMIT 250; -- yes, again
但是为了使这项改革工作顺利进行，需要有新的指标。我不确定是否这些
INDEX(delivery_type, franchise_id, created_at),
INDEX(delivery_type, franchise_id, delivery_target),
或这些
INDEX(delivery_type, created_at),
INDEX(delivery_type, delivery_target),
会更好。全部加4;请EXPLAIN查看它使用的内容。