对这张表，有一个最常用的查询，如何创建好的索引来提高速度答案

【问题标题】：To this table , there is a mostly used query , How to create good index to improve speed对这张表，有一个最常用的查询，如何创建好的索引来提高速度
【发布时间】：2014-01-28 03:06:36
【问题描述】：

这是我的桌子的构造

CREATE TABLE [dbo].[InterfaceMeraAdReport_CAV](
    [ID] [int] IDENTITY(1,1) NOT NULL,
    [reportID] [nvarchar](100) NOT NULL,
    [FromTime] [nvarchar](100) NOT NULL,
    [ToTime] [nvarchar](100) NOT NULL,
    [Customer] [nvarchar](100) NOT NULL,
    [Area] [nvarchar](100) NOT NULL,
    [Vendor] [nvarchar](100) NOT NULL,
    [SuccessCalls] [nvarchar](100) NOT NULL,
    [TotalCalls] [nvarchar](100) NOT NULL,
    [TotalMins] [nvarchar](100) NOT NULL,
    [ASR] [nvarchar](100) NOT NULL,
    [ACD] [nvarchar](100) NOT NULL,
    [Fee] [nvarchar](100) NOT NULL,
    [Cost] [nvarchar](100) NOT NULL,
    [Profix] [nvarchar](100) NOT NULL,
 CONSTRAINT [PK_MeraAdvReport_CA] PRIMARY KEY CLUSTERED 
(
    [ID] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]
) ON [PRIMARY]

两个最常用的查询是这种形式：一个

select  Customer,vendor,SUM(cast(SuccessCalls as int)) as successCalls,
SUM(cast(TotalCalls as int)) as TotalCalls,
SUM(cast(TotalMins as decimal(18,2))) as TotalMins,
case when  SUM(cast(TotalCalls as decimal(18,2)))  = 0  then 0.0 else (SUM(cast(SuccessCalls as decimal(18,2))) /  SUM(cast(TotalCalls as decimal(18,2)))) end as ASR,
case when  SUM(cast(SuccessCalls as decimal(18,2)))  = 0  then 0.0 else (SUM(cast(TotalMins as decimal(18,2))) /  SUM(cast(SuccessCalls as decimal(18,2)))) end as ACD,
SUM(cast(Profix as decimal(18,2))) as profix
from InterfaceMeraAdReport_CAV
where FromTime >= '20140128020000' and ToTime <= '20140128030000' 
 and Customer= '01.2136'  and Area  in ('62817','62818','62819','62859','62877','62878','62879') 
group by Customer,Vendor

两个

select Customer,SUM(cast(SuccessCalls as int)) as successCalls,
SUM(cast(TotalCalls as int)) as TotalCalls,
SUM(cast(TotalMins as decimal(18,2))) as TotalMins,
case when  SUM(cast(TotalCalls as decimal(18,2)))  = 0  then 0.0 else (SUM(cast(SuccessCalls as decimal(18,2))) /  SUM(cast(TotalCalls as decimal(18,2)))) end as ASR,
case when  SUM(cast(SuccessCalls as decimal(18,2)))  = 0  then 0.0 else (SUM(cast(TotalMins as decimal(18,2))) /  SUM(cast(SuccessCalls as decimal(18,2)))) end as ACD
from InterfaceMeraAdReport_CAV
where FromTime >= @timeFrom and ToTime <= @timeTo
 and Customer= @customer  and Area in ('62817','62818','62819','62859','62877','62878','62879') 
group by Customer

这个表每天增加大约300000条记录，所以现在上面的查询变得越来越慢，

我想创建索引来提高速度，但我不知道最有效的方法，谁能告诉我哪些列是最好的索引列

【问题讨论】：

标签： sql-server performance indexing

【解决方案1】：

根据您的数据，您可能会发现FromTime > 20140128020000 尤其是ToTime < 20140128030000 的选择性可能不足以保证仅在其中任一列上建立索引。

所以这给您留下了Customer 和Area - 您需要再次了解表中这些列的数据分布。

假设Customer 的选择性很高，并假设客户与区域高度相关（即客户通常仅来自一个区域），然后尝试使您的索引尽可能窄，例如：

CREATE INDEX IX_MyIndex ON InterfaceMeraAdReport_CAV(Customer)

如果客户与区域不相关，或者如果客户本身没有选择性：

CREATE INDEX IX_MyIndex ON InterfaceMeraAdReport_CAV(Customer, Area)

或者如果 Area 比客户有更好的选择性：

CREATE INDEX IX_MyIndex ON InterfaceMeraAdReport_CAV(Area, Customer)

或者，如果报告仅针对最近的数据运行并且存在大量遗留数据，那么FromTime 可能是有选择性的：

CREATE INDEX IX_MyIndex ON InterfaceMeraAdReport_CAV(FromTime, Customer)

等等。即，您需要了解您的数据才能对索引做出决策。

由于您在选择中仅获取 6 个列，因此包含覆盖索引也可能有意义。

CREATE INDEX IX_MyIndex ON InterfaceMeraAdReport_CAV(Customer, Area) 
INCLUDE (Vendor, SuccessCalls, TotalCalls, TotalMins, Profix);

或者，如果这 2 个查询是针对此表的唯一个重要查询，那么您还应该考虑根据这些查询选择 CLUSTERED 索引，例如优化最少的页面读取。 Customer、Area 和FromTime 可能是最合适的。

（如果你把它设为聚集索引，显然你不需要覆盖索引）。

【讨论】：