MySQL选择优化帮助？

时间：2010-08-24 22:32:37

标签： mysql

这是我在我的某个网站上经常使用的SELECT查询的一个广泛示例。由于我们的主机加载页面时间很慢，因此我们遇到了非常糟糕的问题，因此我尝试尽我所能优化网站使用的每一段代码。谈到MySQL，我不是专家，所以我希望你们中的一些人可能会有所帮助。这是我想要进一步优化的查询 - 

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')

基本上它会检查1个表（table_1）并拉出与table_2，table_3和table_4中找不到的所有匹配的行。我确信除了多个子选择之外，还有一种更有效的方法。任何帮助是极大的赞赏！在此先感谢：）

更新：基本上我很想知道的是，是否有比查询中多个子选择更快的东西？我确信有一些方法可以从一个表中获取结果，这些表在多个其他表中不存在，这比执行子选择更有效...表之间的唯一共性是table_1中的ID，与其他3个表中的每个表中的另一列相同（这是我目前正在使用子选择对其进行检查）。不幸的是，我只是想弄清楚这个查询更有效的方法是什么......感谢大家到目前为止的输入！

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')

3 个答案:

答案 0 :(得分：0)

您是否尝试过查询查询。如果您不熟悉EXPLAIN，它将生成一个报告，显示如何执行查询，尤其是使用哪些索引，并且可能显示索引在哪里可取但不存在。

我过去也发现NOT IN有时会非常缓慢。也许重写NOT IN作为NOT EXISTS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')

答案 1 :(得分：0)

IDFMA

请发布以下脚本的结果，以便我们详细分析您的查询。如果你也可以将结果粘贴到http://pastie.org/说{{3}}，那也很棒。

感谢

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');

答案 2 :(得分：0)

您可以将此单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。这将使其更具可读性，并且可能运行得更快......

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