ruby-on-rails - rails 查询超时::错误:执行已过期

Question

我有一个简单的查询，但它显示了Timeout::Error: execution expired，而且我正在使用 rack::timeout

SELECT  SUM(total_checks) as totalcheck FROM "orders"  WHERE 
(orders.order_status_id NOT IN (15, 17)) AND (orders.check_id = 36) AND 
(orders.pass_id = '49') AND (orders.created_at BETWEEN '2016-02-29 
22:00:00.000000' AND '2016-03-02 22:00:00.000000') LIMIT 1

此外，我的订单总数约为 9762797，此查询有任何问题吗？

什么时候搞定的解释分析

----------
Limit  (cost=153.76..153.77 rows=1 width=5) (actual time=14622.323..14622.324
rows=1 loops=1)
->  Aggregate  (cost=153.76..153.77 rows=1 width=5) (actual 
time=14622.322..14622.322 rows=1 loops=1)

 ->  Index Scan using idx_orders_check_and_pass on orders 
(cost=0.43..153.76 rows=1 width=5) (actual time=2739.717..14621.649 rows=141 
loops=1)
       Index Cond: ((check_id = 36) AND (pass_id = 49))
       Filter: ((order_status_id <> ALL ('{15,17}'::integer[])) AND 
(created_at >= '2016-02-29 22:00:00'::timestamp without time zone) AND 
(created_at <= '2016-03-02 22:00:00'::timestamp without time zone))
       Rows Removed by Filter: 42396
Total runtime: 14622.524 ms

(7 rows)

Answer 1

您有相当大的表来运行 SUM。我建议使用一些缓存机制来避免使用此查询，因为 14 秒很多。

例如，我建议创建新表 total_orders_checks 并在其中存储总支票。每次更新 orders 表 total_checks 值时都需要更新它，它可能不适合您的应用程序设计，但您肯定会得到 total_checks 快得多。