MySQL優化

Question

我試圖加快我的網站和主要問題上它幾乎所有頁面上運行一個查詢（代碼如下）。 LIMIT更改加快，但我需要使用LIMIT 99 :( 24速度是〜0.06秒 在100〜0.105秒 服務器限制：子查詢（SELECT video_names.name ...）不能改變加入

SELECT `videos`.`name`, `videos`.`episodes`, `videos`.`is_ended`, `videos`.`id`, `videos`.`logo`, `videos`.`type`, `user_videos`.`episode`, 
(SELECT `video_names`.`name` 
FROM (`video_names`) 
WHERE `video_names`.`vid_id` = `videos`.`id` LIMIT 1) as alt_name 
FROM (`videos`) 
JOIN `user_videos` ON `user_videos`.`vid_id` = `videos`.`id` 
WHERE `user_videos`.`user_id` = '1' 
AND `user_videos`.`status` = '1' 
GROUP BY `videos`.`id` 
ORDER BY `last_change` desc 
LIMIT 24 

Answer 1

我測試所有變種來自StackOverflow和其他來源的巨人。最高車速：

1. 從問題查詢（時間）
2. 回答"Couldn't that work"（時間×2）
3. 查詢，而不sql_big_selects=1（時間X4.5）
4. 查詢與sql_big_selects=1（時間X5和慢）

Answer 2

莫非不是工作？

SELECT 
    `videos`.`name` 
, `videos`.`episodes` 
, `videos`.`is_ended` 
, `videos`.`id` 
, `videos`.`logo` 
, `videos`.`type` 
, `user_videos`.`episode` 
, `video_names`.`name` 
FROM `videos` 
, `user_videos` 
, `video_names` 
WHERE TRUE 
    AND `user_videos`.`user_id` = '1' 
    AND `user_videos`.`status` = '1' 
    AND `videos`.`id` = `user_videos`.`vid_id` 
    AND `videos`.`id` = `video_names`.`vid_id` 
GROUP BY `videos`.`id` 
ORDER BY `last_change` DESC 
LIMIT 24 
; 

Answer 3

試試這個腳本

SELECT 
    `v`.`name` 
    , `v`.`episodes` 
    , `v`.`is_ended` 
    , `v`.`id` 
    , `v`.`logo` 
    , `v`.`type` 
    , `u`.`episode` 
    , `v`.`alt_name` 
FROM `user_videos` `u` 
JOIN (
    SELECT `videos`.*, `video_names`.`name` AS alt_name FROM `videos` 
    JOIN `video_names` ON `video_names`.`vid_id` = `videos`.`id` 
    GROUP BY `videos`.`id` 
) `v` ON `u`.`vid_id` = `c`.`id` 
WHERE `u`.`user_id` = '1' 
AND `u`.`status` = '1' 
ORDER BY `last_change` DESC 
LIMIT 24;