在MySQL中查询速度很快，但在PHP中速度很慢

我们在其中一个网站上的搜索引擎速度非常慢。我打开了慢速查询日志并记录了花费时间超过10秒的所有查询。仅记录来自此搜索引擎的查询。这里是日志的一个例子：在MySQL中查询速度很快，但在PHP中速度很慢

# Time: 120801 9:21:42 
# [email protected]: ********** @ localhost [] 
# Query_time: 22.156250 Lock_time: 0.000000 Rows_sent: 33 Rows_examined: 3385401 
SET timestamp=1343805702; 
SELECT *, IF(InSection OR InBranche, 1, 0) AS SorteerKolom FROM(SELECT DISTINCT Plant, Email, Nicename, Displayname, JobTitle, Department, Initials, Lastname, LastnameForSort, 
           search_people.ForeignId, IsVennoot, 
           (Zoekwoorden LIKE '%statutair%') AS SearchTerm, 
           (Displayname LIKE '%statutair%') AS ByName, 
           0 AS InSection, 0 AS InBranche, 1 AS ShowAll, 
           (SELECT COUNT(*) FROM search_hasarticles WHERE UserId = search_people.ForeignId) > 0 AS HasWritten 
          FROM search_people 
          LEFT JOIN search_people_branches ON search_people.ForeignId = search_people_branches.UserId 
          LEFT JOIN search_people_specialismen ON search_people.ForeignId = search_people_specialismen.UserId 
          LEFT JOIN wp_usermeta AS wpu ON (wpu.user_id = search_people.ForeignId) 
          WHERE 
          (
           Firstname LIKE '%statutair%' 
           OR Lastname LIKE '%statutair%' 
           AND Displayname LIKE '%statutair%' 
           OR Email LIKE '%statutair%' 
           OR Address LIKE '%statutair%' 
           OR Initials LIKE '%statutair%' 
           OR Location LIKE '%statutair%' 
           OR Givenname LIKE '%statutair%' 
           OR Nickname LIKE '%statutair%' 
           OR JobTitle LIKE '%statutair%' 
           OR Login LIKE '%statutair%' 
           OR Title LIKE '%statutair%' 
           OR Phone LIKE '%statutair%' 
           OR Fax LIKE '%statutair%' 
           OR Plant LIKE '%statutair%' 
           OR Displayname LIKE '%statutair%' 
           OR Zoekwoorden LIKE '%statutair%' 

          ) 
          AND (1=1) AND search_people.IsHidden = 0 AND search_people.Activated = 1 UNION SELECT DISTINCT Plant, Email, Nicename, Displayname, JobTitle, Department, Initials, Lastname, LastnameForSort, 
           search_people.ForeignId, IsVennoot, 0 AS SearchTerm, 0 AS ByName, 0 AS InSection, 1 AS InBranche, 1 AS ShowAll, 
           (SELECT COUNT(*) FROM search_hasarticles WHERE UserId = search_people.ForeignId) > 0 AS HasWritten 
          FROM search_people 
          LEFT JOIN search_people_branches ON search_people.ForeignId = search_people_branches.UserId 
          LEFT JOIN search_branches ON search_branches.ForeignId = search_people_branches.BrancheId 
          LEFT JOIN search_people_specialismen ON search_people.ForeignId = search_people_specialismen.UserId 
          WHERE Name LIKE '%statutair%' AND (1=1) AND search_people.IsHidden = 0 AND search_people.Activated = 1 UNION SELECT DISTINCT Plant, Email, Nicename, Displayname, JobTitle, Department, Initials, Lastname, LastnameForSort, search_people.ForeignId, IsVennoot, 0 AS SearchTerm, 0 AS ByName, 1 AS InSection, 0 AS InBranche, 1 AS ShowAll, (SELECT COUNT(*) FROM search_hasarticles WHERE UserId = search_people.ForeignId) > 0 AS HasWritten FROM search_people LEFT JOIN search_people_specialismen ON search_people.ForeignId=search_people_specialismen.UserId LEFT JOIN search_specialties ON search_specialties.ForeignId=search_people_specialismen.SpecialismeId LEFT JOIN search_people_branches ON search_people.ForeignId=search_people_branches.UserId WHERE (Name LIKE '%statutair%' OR SearchTerms LIKE '%statutair%') AND (1=1) AND search_people.IsHidden = 0 AND search_people.Activated = 1 UNION SELECT DISTINCT Plant, Email, Nicename, Displayname, JobTitle, Department, Initials, Lastname, LastnameForSort, search_people.ForeignId, IsVennoot, 0 AS SearchTerm, 0 AS ByName, 0 AS InSection, 0 AS InBranche, 0 AS ShowAll, 1 AS HasWritten FROM search_posts LEFT JOIN search_posts_branches ON search_posts.ForeignId=search_posts_branches.PostId LEFT JOIN search_branches ON search_posts_branches.BrancheId=search_branches.ForeignId LEFT JOIN search_people_specialismen ON search_posts.PostAuthor=search_people_specialismen.UserId LEFT JOIN search_specialties ON search_people_specialismen.SpecialismeId=search_specialties.ForeignId INNER JOIN search_people ON search_people.ForeignId=search_posts.PostAuthor WHERE (PostTitle LIKE '%statutair%' OR PostContent LIKE '%statutair%' OR search_branches.Name LIKE '%statutair%' OR search_specialties.Name LIKE '%statutair%') AND PostStatus='publish' AND PostType='post' AND (1=1) AND search_people.IsHidden = 0 AND search_people.Activated = 1) AS search_results ORDER BY SearchTerm DESC, ByName DESC, SorteerKolom DESC, IsVennoot DESC, InSection DESC, InBranche DESC, HasWritten DESC, LastnameForSort ASC, Initials ASC;

正如你可以看到查询了大约22秒执行，如果直接做同样的查询在MySQL中大约需要4秒。

我做了这个相同的查询说明和uotput如下：

id        select_type      table       type        possible_keys     key        key_len       ref        rows        Extra          
1        PRIMARY       <derived2>      ALL        NULL        NULL        NULL        NULL        33        Using filesort       
2        DERIVED       search_people     ALL        NULL        NULL        NULL        NULL        323        Using where; Using temporary    
2        DERIVED       search_people_branches   ALL        NULL        NULL        NULL        NULL        2013        Distinct         
2        DERIVED       search_people_specialismen  ALL        NULL        NULL        NULL        NULL        1013        Distinct         
2        DERIVED       wpu        ref        user_id       user_id       8        wordpress.search_people.ForeignId 84        Using index; Distinct      
3        DEPENDENT SUBQUERY    search_hasarticles    ALL        NULL        NULL        NULL        NULL        101        Using where        
4        UNION       search_branches     ALL        NULL        NULL        NULL        NULL        19        Using where; Using temporary    
4        UNION       search_people     ALL        NULL        NULL        NULL        NULL        323        Using where; Using join buffer   
4        UNION       search_people_specialismen  ALL        NULL        NULL        NULL        NULL        1013        Distinct         
4        UNION       search_people_branches   ALL        NULL        NULL        NULL        NULL        2013        Using where; Distinct; Using join buffer 
5        DEPENDENT SUBQUERY    search_hasarticles    ALL        NULL        NULL        NULL        NULL        101        Using where        
6        UNION       search_specialties    ALL        NULL        NULL        NULL        NULL        73        Using where; Using temporary    
6        UNION       search_people     ALL        NULL        NULL        NULL        NULL        323        Using where; Using join buffer   
6        UNION       search_people_specialismen  ALL        NULL        NULL        NULL        NULL        1013        Using where; Distinct; Using join buffer 
6        UNION       search_people_branches   ALL        NULL        NULL        NULL        NULL        2013        Distinct         
7        DEPENDENT SUBQUERY    search_hasarticles    ALL        NULL        NULL        NULL        NULL        101        Using where        
8        UNION       search_posts      ALL        NULL        NULL        NULL        NULL        15860       Using where; Using temporary    
8        UNION       search_posts_branches   ALL        NULL        NULL        NULL        NULL        149        Distinct         
8        UNION       search_branches     ALL        NULL        NULL        NULL        NULL        19        Distinct         
8        UNION       search_people_specialismen  ALL        NULL        NULL        NULL        NULL        1013        Distinct         
8        UNION       search_specialties    ALL        NULL        NULL        NULL        NULL        73        Using where; Distinct      
8        UNION       search_people     ALL        NULL        NULL        NULL        NULL        323        Using where; Distinct; Using join buffer 
           UNION RESULT      <union2,4,6,8>     ALL        NULL        NULL        NULL        NULL        NULL

任何人都可以解释为什么相同的查询是在我的网站然后直接在MySQL SOOO慢得多？或者更重要的是，有没有办法在本网站上更快地进行查询？

如果您需要更多信息进行故障排除，请大声呼救，我会尽力为您提供帮助。

感谢这么多提前，月

这是查询的简介：

+----------------------+----------+ 
| Status    | Duration | 
+----------------------+----------+ 
| starting    | 0.000431 | 
| Opening tables  | 0.002004 | 
| System lock   | 0.000012 | 
| Table lock   | 0.000502 | 
| optimizing   | 0.000033 | 
| statistics   | 0.000042 | 
| preparing   | 0.000034 | 
| Creating tmp table | 0.000085 | 
| executing   | 0.000004 | 
| Copying to tmp table | 0.001957 | 
| Sending data   | 0.000006 | 
| optimizing   | 0.000025 | 
| statistics   | 0.000027 | 
| preparing   | 0.000041 | 
| Creating tmp table | 0.000114 | 
| executing   | 0.000001 | 
| Copying to tmp table | 0.000058 | 
| Sending data   | 0.000004 | 
| optimizing   | 0.000021 | 
| statistics   | 0.000027 | 
| preparing   | 0.000037 | 
| Creating tmp table | 0.000095 | 
| executing   | 0.000003 | 
| Copying to tmp table | 0.007376 | 
| optimizing   | 0.000013 | 
| statistics   | 0.000017 | 
| preparing   | 0.000011 | 
| executing   | 0.000005 | 
| Sending data   | 0.001248 | 
| executing   | 0.000014 | 
| Sending data   | 0.001894 | 
| executing   | 0.000007 | 
| Sending data   | 0.003249 | 
| executing   | 0.000004 | 
| Sending data   | 0.001487 | 
| executing   | 0.000001 | 
| Sending data   | 0.000433 | 
| executing   | 0.000001 | 
| Sending data   | 0.012100 | 
| executing   | 0.000006 | 
| Sending data   | 0.000713 | 
| executing   | 0.000002 | 
| Sending data   | 0.000681 | 
| executing   | 0.000001 | 
| Sending data   | 0.015382 | 
| executing   | 0.000005 | 
| Sending data   | 0.001048 | 
| executing   | 0.000002 | 
| Sending data   | 0.000916 | 
| executing   | 0.000004 | 
| Sending data   | 0.000421 | 
| executing   | 0.000001 | 
| Sending data   | 0.000561 | 
| executing   | 0.000001 | 
| Sending data   | 0.005126 | 
| executing   | 0.000008 | 
| Sending data   | 0.014534 | 
| executing   | 0.000004 | 
| Sending data   | 0.001666 | 
| executing   | 0.000006 | 
| Sending data   | 0.001641 | 
| Sending data   | 0.000203 | 
| optimizing   | 0.000045 | 
| statistics   | 0.000050 | 
| preparing   | 0.000049 | 
| Creating tmp table | 0.000182 | 
| executing   | 0.000002 | 
| Copying to tmp table | 5.101209 | 
| Sending data   | 0.000226 | 
| optimizing   | 0.000007 | 
| statistics   | 0.000008 | 
| preparing   | 0.000007 | 
| executing   | 0.000001 | 
| Sending data   | 0.000217 | 
| removing tmp table | 0.000044 | 
| Sending data   | 0.000007 | 
| removing tmp table | 0.000012 | 
| Sending data   | 0.000017 | 
| removing tmp table | 0.000011 | 
| Sending data   | 0.000005 | 
| removing tmp table | 0.000033 | 
| Sending data   | 0.000008 | 
| removing tmp table | 0.000030 | 
| Sending data   | 0.000009 | 
| init     | 0.000044 | 
| optimizing   | 0.000005 | 
| statistics   | 0.000004 | 
| preparing   | 0.000007 | 
| executing   | 0.000002 | 
| Sorting result  | 0.000074 | 
| Sending data   | 0.000164 | 
| end     | 0.000003 | 
| query end   | 0.000005 | 
| freeing items  | 0.000210 | 
| removing tmp table | 0.000061 | 
| closing tables  | 0.000051 | 
| logging slow query | 0.000003 | 
| cleaning up   | 0.000026 | 
+----------------------+----------+

来源

2012-08-01 Jan

*上帝的母亲... * – MacMac 2012-08-01 10:04:20

欢迎来到SO，祝贺你的演出第一个问题:) – Dale 2012-08-01 10:05:12

如果传回的数据很重要，它将需要一段时间才能返回到您的PHP应用程序。我会认真地建议设置一个sqlfiddle与这个问题，因为你的查询是巨大的，很难打破没有看到它的行动（或至少对我来说）它 – Lee 2012-08-01 10:05:43

在我看来，你必须对大量列设置索引。请阅读以下内容：http://dev.mysql.com/doc/refman/5.0/en/explain-output.html 要加快查询速度，请首先在JOIN语句中使用的每列设置一个索引。如果这不能加快速度，请在列上设置一个索引，以检查您的位置。此外，或运算符是缓慢的，并在与所有OR的块还有一个AND。也许你可以跳过一些OR，比如'首字母缩写'（但这当然是一个疯狂的猜测......）

来源

2012-08-01 16:24:58

我看到很多的非可转位条件，如Firstname LIKE '%statutair%'。一种可能性是MySQL实际使用其results cache，而PHP无法利用结果缓存。这可能发生，例如，如果您使用ATTR_EMULATE_PREPARES option disabled的PDO。

内从MySQL的测试时，如发现，添加SQL_NO_CACHE条款：

SELECT SQL_NO_CACHE id, name FROM customer;

来源

2012-08-01 10:18:33

嗨瓦尔罗。我提到的4s是一个非缓存的结果。如果我在MySQL中重新查询，结果显示在大约30ms。该网站似乎也缓存。如果我再次使用相同的搜索词，屏幕上的结果会非常快。 – Jan 2012-08-01 11:27:15

@Jan - 嗯，这只是在黑暗中拍摄而已:) – 2012-08-01 11:35:56

这当然是赞赏！ :) – Jan 2012-08-01 13:25:39

在MySQL中查询速度很快，但在PHP中速度很慢

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