MySQL选择优化帮助？

这是我在我的一个站点上经常使用的SELECT查询的一个广泛示例。我们的主机的页面加载速度很慢，这是一个非常糟糕的问题，所以我正在尽我所能优化网站使用的每一段代码。我不是MySQL方面的专家，所以我希望你们中的一些人能有所帮助。这是我试图进一步优化的查询-

Select ID, Col1, Col2, Col3, Col4, Col5, Col6, Col7, Col8, Col9, Col10, Col11, Col12, Col13, Col14, Col15 From table_1
Where Active = '1' And Col2 LIKE '%Cat%' And Col3 <> 'blah' And Col3 <> 'blah1'  And Col3 <> 'blah2' And Col3 <> 'blah3' And Col3 <> 'blah4' And Col3 <> 'blah5' And Col3 <> 'blah6'
And ID Not In (Select t2ID From table_2 Where table_2.t2ID = table_1.ID And table_2.Col1 = '1' And table_2.Col2 = '1')
And ID Not In (Select t3ID From table_3 Where table_3.t3ID = table_1.ID And table_3.Col1 = '1')
And ID Not In (Select t4ID From table_4 Where table_4.t4ID = table_1.ID And table_4.Col1 = '1')

基本上，它检查表1、表1，并提取表2、表3和表4中未找到的所有匹配行。我相信除了多个子选择之外，还有一种更有效的方法。非常感谢您的帮助！提前感谢：

更新：基本上我想知道的是，有没有比查询中的多个子选择更快的东西？我确信有某种方法可以从一个表中获得结果，而这个表在多个其他表中并不存在，这比进行子选择要有效得多。。。两个表之间唯一的共同点是，表_1中的ID与其他3个表中的每一个表中的另一列相同，这就是我目前正在使用子选择项对其进行检查的内容。不幸的是，我只是不知道做这个查询更有效的方法是什么。。。感谢大家迄今为止的投入

表格布局

mysql> show create table campaigns\G  
*************************** 1. row ***************************  
Table: campaigns  
Create Table: CREATE TABLE `campaigns` (  
`ID` int(11) NOT NULL auto_increment,  
`CreatedOn` datetime NOT NULL,  
`AddedBy` varchar(75) default NULL,  
`pCampaignName` varchar(255) default NULL,  
`CampaignName` varchar(255) default NULL,  
`CampaignValue` decimal(65,2) default '0.00',  
`CampaignPayout` decimal(65,2) NOT NULL default '0.00',  
`CampaignT` double NOT NULL default '0',  
`CampaignSD` double NOT NULL default '0',  
`ReportingTime` varchar(255) default NULL,  
`CampaignExpiration` varchar(100) default NULL,  
`DurationType` varchar(100) default NULL,  
`Countries` varchar(100) default NULL,  
`CampaignDescription` longtext,  
`CampaignRequirements` longtext,  
`CampaignType` varchar(50) default NULL,  
`CampaignID` varchar(255) default NULL,  
`BannerImageWidth` int(10) NOT NULL default '0',  
`BannerImageHeight` int(10) NOT NULL default '0',  
`BannerImageURL` varchar(255) default NULL,  
`BannerImageAlternateText` varchar(255) default NULL,  
`DisplayBanner` int(1) NOT NULL default '0',  
`CampaignCode` longtext,  
`CampaignURL` longtext,  
`CampaignActive` int(1) NOT NULL default '0',  
`Status` varchar(255) default NULL,  
`Affiliate` varchar(255) default NULL,  
`NewOfferEmailSent` int(1) unsigned NOT NULL default '0',  
`NumberApproved` double(65,2) NOT NULL default '0.00',  
`NumberLeads` double NOT NULL default '0',  
`ThumbsUp` double NOT NULL default '0',  
`ThumbsDown` double NOT NULL default '0',  
`CampaignPoints` double NOT NULL default '0',  
`UserRatingUp` double NOT NULL default '0',  
`UserRatingDown` double NOT NULL default '0',  
PRIMARY KEY  (`ID`)  
) ENGINE=MyISAM AUTO_INCREMENT=1608 DEFAULT CHARSET=utf8  
1 row in set (0.09 sec)  

mysql> show indexes from campaigns\G  
*************************** 1. row ***************************  
Table: campaigns  
Non_unique: 0  
Key_name: PRIMARY  
Seq_in_index: 1  
Column_name: ID  
Collation: A  
Cardinality: 1596  
Sub_part: NULL  
Packed: NULL  
Null:  
Index_type: BTREE  
Comment:  
1 row in set (0.10 sec)  

mysql>  
mysql> show create table acampaigns\G  
*************************** 1. row ***************************  
Table: acampaigns  
Create Table: CREATE TABLE `acampaigns` (  
`ID` int(11) NOT NULL auto_increment,  
`CreatedOn` datetime NOT NULL,  
`CampaignName` varchar(255) default NULL,  
`CampaignRequirements` longtext,  
`CampaignURL` longtext,  
`CampaignValue` decimal(65,2) NOT NULL,  
`CampaignPayout` decimal(65,2) NOT NULL,  
`CampaignReferralCommissionTier1` decimal(65,2) NOT NULL default '0.20',  
`CampaignReferralCommissionTier2` decimal(65,2) NOT NULL default '0.10',  
`CampaignT` double NOT NULL default '0',  
`CampaignSD` double NOT NULL default '0',  
`CampaignType` varchar(255) default NULL,  
`CampaignID` varchar(100) default NULL,  
`CampaignExpiration` varchar(100) default NULL,  
`CampaignReturnStatus` varchar(100) default NULL,  
`CampaignStatus` varchar(255) default NULL,  
`pCampaignID` int(11) NOT NULL,  
`pCampaignName` varchar(255) default NULL,  
`pUserID` int(11) NOT NULL,  
`pUsername` varchar(75) default NULL,  
`pUserIPAddress` varchar(30) default NULL,  
`ApprovedOn` datetime NOT NULL,  
`MarkedDone` int(1) NOT NULL default '0',  
`Notes` longtext,  
`PaidOn` datetime default NULL,  
`cBonus` decimal(65,2) NOT NULL default '0.00',  
`ReversedReason` varchar(255) default NULL,  
`CampaignPoints` double NOT NULL default '0',  
`Affiliate` varchar(255) default NULL,  
`RC1Paid` int(1) unsigned NOT NULL default '0',  
`RC2Paid` int(1) unsigned NOT NULL default '0',  
PRIMARY KEY  (`ID`)  
) ENGINE=MyISAM AUTO_INCREMENT=10996 DEFAULT CHARSET=utf8  
1 row in set (0.44 sec)  

mysql> show indexes from acampaigns\G  
*************************** 1. row ***************************  
Table: acampaigns  
Non_unique: 0  
Key_name: PRIMARY  
Seq_in_index: 1  
Column_name: ID  
Collation: A  
Cardinality: 8936  
Sub_part: NULL  
Packed: NULL  
Null:  
Index_type: BTREE  
Comment:  
1 row in set (0.09 sec)  

mysql>  
mysql> show create table bcampaigns\G  
*************************** 1. row ***************************  
Table: bcampaigns  
Create Table: CREATE TABLE `bcampaigns` (  
`ID` int(11) NOT NULL auto_increment,  
`CreatedOn` datetime NOT NULL,  
`pCampaignID` int(11) NOT NULL,  
`ReportedByUserID` int(11) NOT NULL,  
`Status` varchar(255) default NULL,  
`Notes` longtext,  
PRIMARY KEY  (`ID`)  
) ENGINE=MyISAM AUTO_INCREMENT=375 DEFAULT CHARSET=utf8  
1 row in set (0.08 sec)  

mysql> show indexes from bcampaigns\G  
*************************** 1. row ***************************  
Table: bcampaigns  
Non_unique: 0  
Key_name: PRIMARY  
Seq_in_index: 1  
Column_name: ID  
Collation: A  
Cardinality: 0  
Sub_part: NULL  
Packed: NULL  
Null:  
Index_type: BTREE  
Comment:  
1 row in set (0.08 sec)  

mysql>  
mysql> show create table icampaigns\G  
*************************** 1. row ***************************  
Table: icampaigns  
Create Table: CREATE TABLE `icampaigns` (  
`ID` int(11) NOT NULL auto_increment,  
`CreatedOn` datetime NOT NULL,  
`pCampaignID` int(11) default NULL,  
`IgnoredByUserID` int(11) default NULL,  
PRIMARY KEY  (`ID`)  
) ENGINE=MyISAM AUTO_INCREMENT=567 DEFAULT CHARSET=utf8  
1 row in set (0.09 sec)  

mysql> show indexes from icampaigns\G  
*************************** 1. row ***************************  
Table: icampaigns  
Non_unique: 0  
Key_name: PRIMARY  
Seq_in_index: 1  
Column_name: ID  
Collation: A  
Cardinality: 532  
Sub_part: NULL  
Packed: NULL  
Null:  
Index_type: BTREE  
Comment:  
1 row in set (0.40 sec)  

mysql>
mysql> explain Select ID, CreatedOn, pCampaignName, 
CampaignName, CampaignRequirements, CampaignURL, Countries, 
CampaignPayout, CampaignPoints, CampaignT, CampaignSD, CampaignType, 
ReportingTime, NumberApproved, NumberLeads
From campaigns
-> Where CampaignActive = '1' And CampaignType LIKE 'Cat%' 
And CampaignType <> 'DS' And CampaignType <> 'CC'  And CampaignType <> 'PC' 
And CampaignType <> 'PC2' And CampaignType <> 'GCC' And CampaignType <> 'G' 
And CampaignType <> 'R'
-> And ID Not In (Select pCampaignID From acampaigns  
Where campaigns.ID = acampaigns.pCampaignID And MarkedDone = '1' And campaigns.pUserID = '1')
-> And ID Not In (Select pCampaignID From bcampaigns  
Where bcampaigns.pCampaignID = campaigns.ID And  bcampaigns.ReportedByUserID = '1')
-> And ID Not In (Select pCampaignID From icampaigns  
Where icampaigns.pCampaignID = campaigns.ID And icampaigns.IgnoredByUserID = '1')

---

你试过解释你的疑问吗。如果您不熟悉EXPLAIN，它将生成一个报告，显示如何执行查询，特别是使用了哪些索引，并且可能会显示需要索引但不存在索引的位置

我还发现，在过去，不参与有时会非常缓慢。也许重写“不存在即不存在”可能会加快速度

NOT EXISTS (SELECT *
                FROM table_3
                WHERE table_3.t3ID = table_1.ID AND
                      table_3.Col1 = '1')

IDFMA

请发布以下脚本的结果，以便我们可以详细分析您的查询。如果你也能把结果贴在上面，那就太好了

谢谢

show create table table_1\G
show indexes from table_1\G

show create table table_2\G
show indexes from table_2\G

show create table table_3\G
show indexes from table_3\G

show create table table_4\G
show indexes from table_4\G

explain
Select 
 ID, Col1, Col2, Col3, Col4, Col5, Col6, Col7, 
 Col8, Col9, Col10, Col11, Col12, Col13, Col14, Col15 
From 
 table_1
Where 
 Active = '1' And 
 Col2 LIKE '%Cat%' And Col3 <> 'blah' And Col3 <> 'blah1'  And Col3 <> 'blah2' And Col3 <> 'blah3' And 
 Col3 <> 'blah4' And Col3 <> 'blah5' And Col3 <> 'blah6' And 
 ID Not In (Select t2ID From table_2 Where table_2.t2ID = table_1.ID And table_2.Col1 = '1' And table_2.Col2 = '1') And 
 ID Not In (Select t3ID From table_3 Where table_3.t3ID = table_1.ID And table_3.Col1 = '1') And 
 ID Not In (Select t4ID From table_4 Where table_4.t4ID = table_1.ID And table_4.Col1 = '1');

---

您可以将这个查询拆分为多个单独的步骤，并使用临时表将它们放在单个存储过程中。这将使它更具可读性，并且可能运行得更快……

将NOT IN更改为NOT EXISTS似乎是相同的速度，没有显著差异。另外，我解释了查询，它返回的主要是null。表1的读数不到1500行，表2的读数刚刚超过7000行，其他两个表的读数不到500行。除表名和选择类型之外的所有其他内容都为空。我试图构造一个连接查询，它将拉取相同的数据，只是为了看看它是否会更快，但似乎无法得到一个不会抛出错误的连接查询，并获取相同的数据。谢谢你迄今为止的帮助！此代码给出了指向“显示创建表表\u 1\G”和“显示表\u 1\G中的索引”的错误。这可能有助于使用您请求的结果编辑主帖。此查询将由数千名成员每天运行数千次，这就是为什么首先需要优化的原因。我可能错了，但是拆分这个查询会不会占用数据库服务器上更多的资源？