如何识别 MySQL 查询的时间非线性增加？
How do I identify non-linear increase in time for MySQL query?
下面是我运行宁的两个查询。一个需要 75-80 秒，一个需要 1.0-1.5 秒。这两个结果都显示了预期的 50 行 channel_administrators.channel_partner_ids。更快查询和更慢查询之间的区别在于 SELECT 从登录名 table 中选择唯一登录名。登录 table 有 460833 行，我知道这会减慢查询速度。我发现这出乎意料的原因是，当 运行 将此代码单独放在一个 channel_administrators.channel_partner_id 上时，结果会在大约 0.2 到 0.7 秒内返回最大 channel_administrators.channel_partner_id 和 50 个结果我不会'预计它不会超过 50 秒。
我希望时间增加在最坏的情况下是线性的，但时间增加似乎不止于此。这种非线性增加让我觉得我做某事（非常？）错了，但我不知道如何找出我的查询有什么问题。谁能告诉我为什么这个查询中的时间会非线性增加？
我在 post.
底部包含了一些测试查询 运行 和它们的最新时间
编辑：
我认为这种现象的最好例子是看测试 2 和测试 3。这些例子尽可能地精简，它表明 运行 逻辑一次进行得很快，但 50 次进行得非常非常慢。
编辑 2： 我添加了更多数据，在 6.93 秒而不是 75+ 秒内获得了相同的结果。对于我的系统，我认为这是一个 acceptable 结果。我现在就写一篇这个问题的答案。
80 秒查询：
SELECT
info.managed_id,
info.channel_name,
info.registered_users,
info.new_users,
info.active_users,
info.coupon_opens
FROM channel_administrators
LEFT JOIN (
SELECT
channel_partners.id AS managed_id,
channel_partners.name as channel_name,
(
SELECT COUNT(users.id)
FROM users
WHERE users.channel_partner_id = channel_partners.id
) AS registered_users,
(
SELECT COUNT(DISTINCT users.id)
FROM users
WHERE users.channel_partner_id = channel_partners.id
AND users.created_at BETWEEN '2021-06-03' AND '2021-07-03' -- 30 days
) AS new_users,
(
SELECT COUNT(DISTINCT logins.user_id)
FROM logins
WHERE logins.channel_partner_id = channel_partners.id
AND logins.created_at BETWEEN '2021-06-03' AND '2021-07-03' -- 30 days
) AS active_users,
(
SELECT COUNT(coupon_trackings.id) AS coupon_view_count
FROM coupon_trackings
WHERE coupon_trackings.channel_partner_id = channel_partners.id
AND coupon_trackings.created_at BETWEEN '2021-06-03' AND '2021-07-03' -- 30 days
) AS coupon_opens
FROM channel_partners
) AS info
ON managed_id = channel_administrators.channel_partner_id
WHERE channel_administrators.user_id = 54184
ORDER BY info.channel_name
1.5 秒查询（注释掉差异）：
SELECT
info.managed_id,
info.channel_name,
info.registered_users,
info.new_users,
-- info.active_users,
info.coupon_opens
FROM channel_administrators
LEFT JOIN (
SELECT
channel_partners.id AS managed_id,
channel_partners.name as channel_name,
(
SELECT COUNT(users.id)
FROM users
WHERE users.channel_partner_id = channel_partners.id
) AS registered_users,
(
SELECT COUNT(DISTINCT users.id)
FROM users
WHERE users.channel_partner_id = channel_partners.id
AND users.created_at BETWEEN '2021-06-03' AND '2021-07-03' -- 30 days
) AS new_users,
-- (
-- SELECT COUNT(DISTINCT logins.user_id)
-- FROM logins
-- WHERE logins.channel_partner_id = channel_partners.id
-- AND logins.created_at BETWEEN '2021-06-03' AND '2021-07-03' -- 30 days
-- ) AS active_users,
(
SELECT COUNT(coupon_trackings.id) AS coupon_view_count
FROM coupon_trackings
WHERE coupon_trackings.channel_partner_id = channel_partners.id
AND coupon_trackings.created_at BETWEEN '2021-06-03' AND '2021-07-03' -- 30 days
) AS coupon_opens
FROM channel_partners
) AS info
ON managed_id = channel_administrators.channel_partner_id
WHERE channel_administrators.user_id = 54184
ORDER BY info.channel_name
以下是我用来在结果最大的频道上测试个别时间的查询。
测试 1：0.441s - 对于单个最大通道：
SELECT
channel_partners.id AS managed_id,
channel_partners.name as channel_name,
(
SELECT COUNT(users.id)
FROM users
WHERE users.channel_partner_id = channel_partners.id
) AS registered_users,
(
SELECT COUNT(DISTINCT users.id)
FROM users
WHERE users.channel_partner_id = channel_partners.id
AND users.created_at BETWEEN '2021-06-03' AND '2021-07-03' -- 30 days
) AS new_users,
(
SELECT COUNT(DISTINCT logins.user_id)
FROM logins
WHERE logins.channel_partner_id = channel_partners.id
AND logins.created_at BETWEEN '2021-06-03' AND '2021-07-03' -- 30 days
) AS active_users,
(
SELECT COUNT(coupon_trackings.id) AS coupon_view_count
FROM coupon_trackings
WHERE coupon_trackings.channel_partner_id = channel_partners.id
AND coupon_trackings.created_at BETWEEN '2021-06-03' AND '2021-07-03' -- 30 days
) AS coupon_opens
FROM channel_partners
WHERE channel_partners.id = 3255770
测试 2：0.368 秒 - 最大频道的活跃用户数：
SELECT COUNT(DISTINCT logins.user_id)
FROM logins
WHERE logins.channel_partner_id = 3255770
AND logins.created_at BETWEEN '2021-06-03' AND '2021-07-03' -- 30 days
测试三：75.2s 只需登录信息
SELECT
info.managed_id,
info.channel_name,
info.active_users
FROM channel_administrators
LEFT JOIN (
SELECT
channel_partners.id AS managed_id,
channel_partners.name as channel_name,
(
SELECT COUNT(DISTINCT logins.user_id)
FROM logins
WHERE logins.channel_partner_id = channel_partners.id
AND logins.created_at BETWEEN '2021-06-03' AND '2021-07-03' -- 30 days
) AS active_users
FROM channel_partners
) AS info
ON info.managed_id = channel_administrators.channel_partner_id
WHERE channel_administrators.user_id = 54184
测试 4：6.93 秒 - 重写取得进展
SELECT
channel_partners.id AS managed_id,
channel_partners.name as channel_name,
(
SELECT COUNT(users.id)
FROM users
WHERE users.channel_partner_id = channel_partners.id
) AS registered_users,
(
SELECT COUNT(DISTINCT users.id)
FROM users
WHERE users.channel_partner_id = channel_partners.id
AND users.created_at BETWEEN '2021-06-03' AND '2021-07-03' -- 30 days
) AS new_users,
(
SELECT COUNT(DISTINCT logins.user_id)
FROM logins
WHERE logins.channel_partner_id = channel_partners.id
AND logins.created_at BETWEEN '2021-06-03' AND '2021-07-03' -- 30 days
) AS active_users,
(
SELECT COUNT(coupon_trackings.id) AS coupon_view_count
FROM coupon_trackings
WHERE coupon_trackings.channel_partner_id = channel_partners.id
AND coupon_trackings.created_at BETWEEN '2021-06-03' AND '2021-07-03' -- 30 days
) AS coupon_opens
FROM channel_partners
WHERE (channel_partners.id IN (SELECT
channel_administrators.channel_partner_id
FROM channel_administrators
WHERE channel_administrators.user_id = 54184
)
)
编辑：
添加查询结果（删除名称）
80 秒查询：
|managed_id|registered_users|new_users|active_users|coupon_opens|
|----------|----------------|---------|------------|------------|
|14 |1146 |46 |282 |893 |
|27 |2159 |48 |206 |635 |
|15 |2039 |68 |490 |2560 |
|16 |15 |0 |1 |0 |
|20 |1391 |53 |413 |1614 |
|21 |3 |0 |0 |0 |
|43 |1051 |36 |255 |1234 |
|44 |706 |19 |85 |276 |
|46 |16 |0 |4 |8 |
|47 |68 |1 |5 |30 |
|48 |169 |6 |40 |308 |
|49 |408 |13 |118 |434 |
|52 |52 |1 |11 |54 |
|53 |378 |11 |111 |391 |
|54 |34 |1 |5 |57 |
|75 |576 |7 |59 |145 |
|3255347 |773 |12 |99 |167 |
|685131 |142 |0 |9 |91 |
|76 |22 |0 |9 |25 |
|55 |276 |5 |68 |251 |
|56 |2232 |79 |534 |1644 |
|57 |78 |0 |10 |47 |
|58 |708 |10 |109 |364 |
|59 |1274 |42 |465 |1929 |
|60 |133 |0 |37 |97 |
|3 |0 |0 |127 |257 |
|2144749 |0 |0 |4 |40 |
|61 |629 |9 |119 |363 |
|63 |857 |36 |267 |892 |
|64 |49 |1 |13 |21 |
|65 |723 |15 |281 |1152 |
|66 |77 |0 |17 |48 |
|67 |123 |10 |59 |190 |
|68 |693 |8 |191 |387 |
|70 |80 |0 |31 |58 |
|71 |214 |1 |41 |102 |
|72 |104 |2 |23 |49 |
|3255770 |3149 |86 |542 |2280 |
|3255771 |3012 |39 |526 |2056 |
|77 |180 |9 |89 |239 |
|477 |677 |5 |286 |583 |
|478 |335 |191 |235 |2226 |
|479 |162 |12 |51 |159 |
|480 |57 |0 |8 |12 |
|302 |51 |3 |17 |32 |
|303 |213 |37 |116 |598 |
|373109 |9 |3 |6 |4 |
|373110 |10 |2 |5 |0 |
|373111 |29 |9 |16 |29 |
|3255810 |0 |0 |0 |0 |
2秒查询：
|managed_id|registered_users|new_users|coupon_opens|
|----------|----------------|---------|------------|
|14 |1146 |46 |893 |
|27 |2159 |48 |635 |
|15 |2039 |68 |2560 |
|16 |15 |0 |0 |
|20 |1391 |53 |1614 |
|21 |3 |0 |0 |
|43 |1051 |36 |1234 |
|44 |706 |19 |276 |
|46 |16 |0 |8 |
|47 |68 |1 |30 |
|48 |169 |6 |308 |
|49 |408 |13 |434 |
|52 |52 |1 |54 |
|53 |378 |11 |391 |
|54 |34 |1 |57 |
|75 |576 |7 |145 |
|3255347 |773 |12 |167 |
|685131 |142 |0 |91 |
|76 |22 |0 |25 |
|55 |276 |5 |251 |
|56 |2232 |79 |1644 |
|57 |78 |0 |47 |
|58 |708 |10 |364 |
|59 |1274 |42 |1929 |
|60 |133 |0 |97 |
|3 |0 |0 |257 |
|2144749 |0 |0 |40 |
|61 |629 |9 |363 |
|63 |857 |36 |892 |
|64 |49 |1 |21 |
|65 |723 |15 |1152 |
|66 |77 |0 |48 |
|67 |123 |10 |190 |
|68 |693 |8 |387 |
|70 |80 |0 |58 |
|71 |214 |1 |102 |
|72 |104 |2 |49 |
|3255770 |3149 |86 |2280 |
|3255771 |3012 |39 |2056 |
|77 |180 |9 |239 |
|477 |677 |5 |583 |
|478 |335 |191 |2226 |
|479 |162 |12 |159 |
|480 |57 |0 |12 |
|302 |51 |3 |32 |
|303 |213 |37 |598 |
|373109 |9 |3 |4 |
|373110 |10 |2 |0 |
|373111 |29 |9 |29 |
|3255810 |0 |0 |0 |
我仍然不知道为什么这 运行 慢，但我找到了一个提高速度的解决方案，并将显示我如何到达那里的步骤。
首先，在原始问题的测试 2 和测试 3 中，您可以看到对登录 table 的单个查询非常快，但是在查询多个 channel_partner_id 时整个查询变得很慢。我怀疑这与我检查 channel_partner_id 与登录 table.
的方式有关
我重写了查询以从列表而不是 select 中获取 channel_partner_id。最终结果如下所示：
SELECT
channel_partners.id AS managed_id,
channel_partners.name as channel_name,
(
SELECT COUNT(users.id)
FROM users
WHERE users.channel_partner_id = channel_partners.id
) AS registered_users,
(
SELECT COUNT(DISTINCT users.id)
FROM users
WHERE users.channel_partner_id = channel_partners.id
AND users.created_at BETWEEN '2021-06-03' AND '2021-07-03' -- 30 days
) AS new_users,
(
SELECT COUNT(DISTINCT logins.user_id)
FROM logins
WHERE logins.channel_partner_id = channel_partners.id
AND logins.created_at BETWEEN '2021-06-03' AND '2021-07-03' -- 30 days
) AS active_users,
(
SELECT COUNT(coupon_trackings.id) AS coupon_view_count
FROM coupon_trackings
WHERE coupon_trackings.channel_partner_id = channel_partners.id
AND coupon_trackings.created_at BETWEEN '2021-06-03' AND '2021-07-03' -- 30 days
) AS coupon_opens
FROM channel_partners
WHERE (channel_partners.id IN (SELECT
channel_administrators.channel_partner_id
FROM channel_administrators
WHERE channel_administrators.user_id = 54184
)
)
这个查询用了 6.93 秒，这仍然很慢，但它更接近我预期的查询时间。
我无法解释为什么一种方式更快而另一种方式更慢。
每个 table 都需要这个 复合 索引，其中的列按给定顺序排列：
INDEX(channel_partner_id, created_at)
如果您有 channel_partner_id，则删除相应的索引。
将这个“覆盖”索引添加到channel_administrators
INDEX(user_id, channel_partner_id)
并删除 INDEX(user_id)（如果存在）。
通过不嵌套选择来简化查询：
SELECT cp.id AS managed_id,
cp.name as channel_name,
( SELECT COUNT(users.id)
FROM users
WHERE users.channel_partner_id = cp.id
) AS registered_users,
((etc))
FROM channel_partners AS cp
JOIN channel_administrators AS ca
ON cp.managed_id = ca.channel_partner_id
WHERE ca.user_id = 54184
ORDER BY channel_name
提示：考虑更改
created_at BETWEEN '2021-06-03' AND '2021-07-03' -- 30 days
至
created_at >= '2021-06-03'
AND created_at < '2021-06-03' + INTERVAL 30 DAY
或使用 + INTERVAL 1 MONTH（如果更合适）。
如果您仍然有性能问题，让我们看看查询是什么样的和提供SHOW CREATE TABLE.
下面是我运行宁的两个查询。一个需要 75-80 秒，一个需要 1.0-1.5 秒。这两个结果都显示了预期的 50 行 channel_administrators.channel_partner_ids。更快查询和更慢查询之间的区别在于 SELECT 从登录名 table 中选择唯一登录名。登录 table 有 460833 行，我知道这会减慢查询速度。我发现这出乎意料的原因是，当 运行 将此代码单独放在一个 channel_administrators.channel_partner_id 上时，结果会在大约 0.2 到 0.7 秒内返回最大 channel_administrators.channel_partner_id 和 50 个结果我不会'预计它不会超过 50 秒。
我希望时间增加在最坏的情况下是线性的，但时间增加似乎不止于此。这种非线性增加让我觉得我做某事（非常？）错了，但我不知道如何找出我的查询有什么问题。谁能告诉我为什么这个查询中的时间会非线性增加？
我在 post.
底部包含了一些测试查询 运行 和它们的最新时间编辑： 我认为这种现象的最好例子是看测试 2 和测试 3。这些例子尽可能地精简，它表明 运行 逻辑一次进行得很快，但 50 次进行得非常非常慢。
编辑 2： 我添加了更多数据，在 6.93 秒而不是 75+ 秒内获得了相同的结果。对于我的系统，我认为这是一个 acceptable 结果。我现在就写一篇这个问题的答案。
80 秒查询：
SELECT
info.managed_id,
info.channel_name,
info.registered_users,
info.new_users,
info.active_users,
info.coupon_opens
FROM channel_administrators
LEFT JOIN (
SELECT
channel_partners.id AS managed_id,
channel_partners.name as channel_name,
(
SELECT COUNT(users.id)
FROM users
WHERE users.channel_partner_id = channel_partners.id
) AS registered_users,
(
SELECT COUNT(DISTINCT users.id)
FROM users
WHERE users.channel_partner_id = channel_partners.id
AND users.created_at BETWEEN '2021-06-03' AND '2021-07-03' -- 30 days
) AS new_users,
(
SELECT COUNT(DISTINCT logins.user_id)
FROM logins
WHERE logins.channel_partner_id = channel_partners.id
AND logins.created_at BETWEEN '2021-06-03' AND '2021-07-03' -- 30 days
) AS active_users,
(
SELECT COUNT(coupon_trackings.id) AS coupon_view_count
FROM coupon_trackings
WHERE coupon_trackings.channel_partner_id = channel_partners.id
AND coupon_trackings.created_at BETWEEN '2021-06-03' AND '2021-07-03' -- 30 days
) AS coupon_opens
FROM channel_partners
) AS info
ON managed_id = channel_administrators.channel_partner_id
WHERE channel_administrators.user_id = 54184
ORDER BY info.channel_name
1.5 秒查询（注释掉差异）：
SELECT
info.managed_id,
info.channel_name,
info.registered_users,
info.new_users,
-- info.active_users,
info.coupon_opens
FROM channel_administrators
LEFT JOIN (
SELECT
channel_partners.id AS managed_id,
channel_partners.name as channel_name,
(
SELECT COUNT(users.id)
FROM users
WHERE users.channel_partner_id = channel_partners.id
) AS registered_users,
(
SELECT COUNT(DISTINCT users.id)
FROM users
WHERE users.channel_partner_id = channel_partners.id
AND users.created_at BETWEEN '2021-06-03' AND '2021-07-03' -- 30 days
) AS new_users,
-- (
-- SELECT COUNT(DISTINCT logins.user_id)
-- FROM logins
-- WHERE logins.channel_partner_id = channel_partners.id
-- AND logins.created_at BETWEEN '2021-06-03' AND '2021-07-03' -- 30 days
-- ) AS active_users,
(
SELECT COUNT(coupon_trackings.id) AS coupon_view_count
FROM coupon_trackings
WHERE coupon_trackings.channel_partner_id = channel_partners.id
AND coupon_trackings.created_at BETWEEN '2021-06-03' AND '2021-07-03' -- 30 days
) AS coupon_opens
FROM channel_partners
) AS info
ON managed_id = channel_administrators.channel_partner_id
WHERE channel_administrators.user_id = 54184
ORDER BY info.channel_name
以下是我用来在结果最大的频道上测试个别时间的查询。
测试 1：0.441s - 对于单个最大通道：
SELECT
channel_partners.id AS managed_id,
channel_partners.name as channel_name,
(
SELECT COUNT(users.id)
FROM users
WHERE users.channel_partner_id = channel_partners.id
) AS registered_users,
(
SELECT COUNT(DISTINCT users.id)
FROM users
WHERE users.channel_partner_id = channel_partners.id
AND users.created_at BETWEEN '2021-06-03' AND '2021-07-03' -- 30 days
) AS new_users,
(
SELECT COUNT(DISTINCT logins.user_id)
FROM logins
WHERE logins.channel_partner_id = channel_partners.id
AND logins.created_at BETWEEN '2021-06-03' AND '2021-07-03' -- 30 days
) AS active_users,
(
SELECT COUNT(coupon_trackings.id) AS coupon_view_count
FROM coupon_trackings
WHERE coupon_trackings.channel_partner_id = channel_partners.id
AND coupon_trackings.created_at BETWEEN '2021-06-03' AND '2021-07-03' -- 30 days
) AS coupon_opens
FROM channel_partners
WHERE channel_partners.id = 3255770
测试 2：0.368 秒 - 最大频道的活跃用户数：
SELECT COUNT(DISTINCT logins.user_id)
FROM logins
WHERE logins.channel_partner_id = 3255770
AND logins.created_at BETWEEN '2021-06-03' AND '2021-07-03' -- 30 days
测试三：75.2s 只需登录信息
SELECT
info.managed_id,
info.channel_name,
info.active_users
FROM channel_administrators
LEFT JOIN (
SELECT
channel_partners.id AS managed_id,
channel_partners.name as channel_name,
(
SELECT COUNT(DISTINCT logins.user_id)
FROM logins
WHERE logins.channel_partner_id = channel_partners.id
AND logins.created_at BETWEEN '2021-06-03' AND '2021-07-03' -- 30 days
) AS active_users
FROM channel_partners
) AS info
ON info.managed_id = channel_administrators.channel_partner_id
WHERE channel_administrators.user_id = 54184
测试 4：6.93 秒 - 重写取得进展
SELECT
channel_partners.id AS managed_id,
channel_partners.name as channel_name,
(
SELECT COUNT(users.id)
FROM users
WHERE users.channel_partner_id = channel_partners.id
) AS registered_users,
(
SELECT COUNT(DISTINCT users.id)
FROM users
WHERE users.channel_partner_id = channel_partners.id
AND users.created_at BETWEEN '2021-06-03' AND '2021-07-03' -- 30 days
) AS new_users,
(
SELECT COUNT(DISTINCT logins.user_id)
FROM logins
WHERE logins.channel_partner_id = channel_partners.id
AND logins.created_at BETWEEN '2021-06-03' AND '2021-07-03' -- 30 days
) AS active_users,
(
SELECT COUNT(coupon_trackings.id) AS coupon_view_count
FROM coupon_trackings
WHERE coupon_trackings.channel_partner_id = channel_partners.id
AND coupon_trackings.created_at BETWEEN '2021-06-03' AND '2021-07-03' -- 30 days
) AS coupon_opens
FROM channel_partners
WHERE (channel_partners.id IN (SELECT
channel_administrators.channel_partner_id
FROM channel_administrators
WHERE channel_administrators.user_id = 54184
)
)
编辑： 添加查询结果（删除名称）
80 秒查询：
|managed_id|registered_users|new_users|active_users|coupon_opens|
|----------|----------------|---------|------------|------------|
|14 |1146 |46 |282 |893 |
|27 |2159 |48 |206 |635 |
|15 |2039 |68 |490 |2560 |
|16 |15 |0 |1 |0 |
|20 |1391 |53 |413 |1614 |
|21 |3 |0 |0 |0 |
|43 |1051 |36 |255 |1234 |
|44 |706 |19 |85 |276 |
|46 |16 |0 |4 |8 |
|47 |68 |1 |5 |30 |
|48 |169 |6 |40 |308 |
|49 |408 |13 |118 |434 |
|52 |52 |1 |11 |54 |
|53 |378 |11 |111 |391 |
|54 |34 |1 |5 |57 |
|75 |576 |7 |59 |145 |
|3255347 |773 |12 |99 |167 |
|685131 |142 |0 |9 |91 |
|76 |22 |0 |9 |25 |
|55 |276 |5 |68 |251 |
|56 |2232 |79 |534 |1644 |
|57 |78 |0 |10 |47 |
|58 |708 |10 |109 |364 |
|59 |1274 |42 |465 |1929 |
|60 |133 |0 |37 |97 |
|3 |0 |0 |127 |257 |
|2144749 |0 |0 |4 |40 |
|61 |629 |9 |119 |363 |
|63 |857 |36 |267 |892 |
|64 |49 |1 |13 |21 |
|65 |723 |15 |281 |1152 |
|66 |77 |0 |17 |48 |
|67 |123 |10 |59 |190 |
|68 |693 |8 |191 |387 |
|70 |80 |0 |31 |58 |
|71 |214 |1 |41 |102 |
|72 |104 |2 |23 |49 |
|3255770 |3149 |86 |542 |2280 |
|3255771 |3012 |39 |526 |2056 |
|77 |180 |9 |89 |239 |
|477 |677 |5 |286 |583 |
|478 |335 |191 |235 |2226 |
|479 |162 |12 |51 |159 |
|480 |57 |0 |8 |12 |
|302 |51 |3 |17 |32 |
|303 |213 |37 |116 |598 |
|373109 |9 |3 |6 |4 |
|373110 |10 |2 |5 |0 |
|373111 |29 |9 |16 |29 |
|3255810 |0 |0 |0 |0 |
2秒查询：
|managed_id|registered_users|new_users|coupon_opens|
|----------|----------------|---------|------------|
|14 |1146 |46 |893 |
|27 |2159 |48 |635 |
|15 |2039 |68 |2560 |
|16 |15 |0 |0 |
|20 |1391 |53 |1614 |
|21 |3 |0 |0 |
|43 |1051 |36 |1234 |
|44 |706 |19 |276 |
|46 |16 |0 |8 |
|47 |68 |1 |30 |
|48 |169 |6 |308 |
|49 |408 |13 |434 |
|52 |52 |1 |54 |
|53 |378 |11 |391 |
|54 |34 |1 |57 |
|75 |576 |7 |145 |
|3255347 |773 |12 |167 |
|685131 |142 |0 |91 |
|76 |22 |0 |25 |
|55 |276 |5 |251 |
|56 |2232 |79 |1644 |
|57 |78 |0 |47 |
|58 |708 |10 |364 |
|59 |1274 |42 |1929 |
|60 |133 |0 |97 |
|3 |0 |0 |257 |
|2144749 |0 |0 |40 |
|61 |629 |9 |363 |
|63 |857 |36 |892 |
|64 |49 |1 |21 |
|65 |723 |15 |1152 |
|66 |77 |0 |48 |
|67 |123 |10 |190 |
|68 |693 |8 |387 |
|70 |80 |0 |58 |
|71 |214 |1 |102 |
|72 |104 |2 |49 |
|3255770 |3149 |86 |2280 |
|3255771 |3012 |39 |2056 |
|77 |180 |9 |239 |
|477 |677 |5 |583 |
|478 |335 |191 |2226 |
|479 |162 |12 |159 |
|480 |57 |0 |12 |
|302 |51 |3 |32 |
|303 |213 |37 |598 |
|373109 |9 |3 |4 |
|373110 |10 |2 |0 |
|373111 |29 |9 |29 |
|3255810 |0 |0 |0 |
我仍然不知道为什么这 运行 慢，但我找到了一个提高速度的解决方案，并将显示我如何到达那里的步骤。
首先，在原始问题的测试 2 和测试 3 中，您可以看到对登录 table 的单个查询非常快，但是在查询多个 channel_partner_id 时整个查询变得很慢。我怀疑这与我检查 channel_partner_id 与登录 table.
我重写了查询以从列表而不是 select 中获取 channel_partner_id。最终结果如下所示：
SELECT
channel_partners.id AS managed_id,
channel_partners.name as channel_name,
(
SELECT COUNT(users.id)
FROM users
WHERE users.channel_partner_id = channel_partners.id
) AS registered_users,
(
SELECT COUNT(DISTINCT users.id)
FROM users
WHERE users.channel_partner_id = channel_partners.id
AND users.created_at BETWEEN '2021-06-03' AND '2021-07-03' -- 30 days
) AS new_users,
(
SELECT COUNT(DISTINCT logins.user_id)
FROM logins
WHERE logins.channel_partner_id = channel_partners.id
AND logins.created_at BETWEEN '2021-06-03' AND '2021-07-03' -- 30 days
) AS active_users,
(
SELECT COUNT(coupon_trackings.id) AS coupon_view_count
FROM coupon_trackings
WHERE coupon_trackings.channel_partner_id = channel_partners.id
AND coupon_trackings.created_at BETWEEN '2021-06-03' AND '2021-07-03' -- 30 days
) AS coupon_opens
FROM channel_partners
WHERE (channel_partners.id IN (SELECT
channel_administrators.channel_partner_id
FROM channel_administrators
WHERE channel_administrators.user_id = 54184
)
)
这个查询用了 6.93 秒，这仍然很慢，但它更接近我预期的查询时间。
我无法解释为什么一种方式更快而另一种方式更慢。
每个 table 都需要这个 复合 索引，其中的列按给定顺序排列：
INDEX(channel_partner_id, created_at)
如果您有 channel_partner_id，则删除相应的索引。
将这个“覆盖”索引添加到channel_administrators
INDEX(user_id, channel_partner_id)
并删除 INDEX(user_id)（如果存在）。
通过不嵌套选择来简化查询：
SELECT cp.id AS managed_id,
cp.name as channel_name,
( SELECT COUNT(users.id)
FROM users
WHERE users.channel_partner_id = cp.id
) AS registered_users,
((etc))
FROM channel_partners AS cp
JOIN channel_administrators AS ca
ON cp.managed_id = ca.channel_partner_id
WHERE ca.user_id = 54184
ORDER BY channel_name
提示：考虑更改
created_at BETWEEN '2021-06-03' AND '2021-07-03' -- 30 days
至
created_at >= '2021-06-03'
AND created_at < '2021-06-03' + INTERVAL 30 DAY
或使用 + INTERVAL 1 MONTH（如果更合适）。
如果您仍然有性能问题，让我们看看查询是什么样的和提供SHOW CREATE TABLE.