查询计划优化器是否适用于已连接/已过滤的表值函数？

在SQLSERVER 2005中,我使用表值函数作为从大表(传递日期范围或此类参数)对子集数据执行任意聚合的便捷方式.

我在大型查询中使用这些作为联合计算,我想知道查询计划优化器是否在每种情况下都能很好地与它们配合使用,或者我是否更好地在我的大型查询中取消这样的计算.

如果有意义,查询计划优化器是否会删除表值函数？

如果没有,你建议什么,以避免手动取消它们会发生代码重复？

如果是,您如何从执行计划中识别出来？

代码示例:

create table dbo.customers (
    [key] uniqueidentifier
    , constraint pk_dbo_customers
        primary key ([key])
)
go

/* assume large amount of data */
create table dbo.point_of_sales (
    [key] uniqueidentifier
    , customer_key uniqueidentifier
    , constraint pk_dbo_point_of_sales
        primary key ([key])
)
go

create table dbo.product_ranges (
    [key] uniqueidentifier
    , constraint pk_dbo_product_ranges
        primary key ([key])
)
go

create table dbo.products (
    [key] uniqueidentifier
    , product_range_key uniqueidentifier
    , release_date datetime
    , constraint pk_dbo_products 
        primary key ([key])
    , constraint fk_dbo_products_product_range_key 
        foreign key (product_range_key) 
        references dbo.product_ranges ([key])
)
go

.

/* assume large amount of data */
create table dbo.sales_history (
    [key] uniqueidentifier
    , product_key uniqueidentifier
    , point_of_sale_key uniqueidentifier
    , accounting_date datetime
    , amount money
    , quantity int
    , constraint pk_dbo_sales_history
        primary key ([key])
    , constraint fk_dbo_sales_history_product_key
        foreign key (product_key)
        references dbo.products ([key])
    , constraint fk_dbo_sales_history_point_of_sale_key
        foreign key (point_of_sale_key)
        references dbo.point_of_sales ([key])
)
go

create function dbo.f_sales_history_..snip.._date_range
(
    @accountingdatelowerbound datetime,
         @accountingdateupperbound datetime
)
returns table as
return (
    select
                  pos.customer_key
        , sh.product_key
        , sum(sh.amount) amount
        , sum(sh.quantity) quantity
    from 
        dbo.point_of_sales pos
        inner join dbo.sales_history sh 
            on sh.point_of_sale_key = pos.[key]
    where
                  sh.accounting_date between 
                      @accountingdatelowerbound and 
                      @accountingdateupperbound
    group by
                  pos.customer_key
                  , sh.product_key
)
go

-- TODO: insert some data

-- this is a table containing a selection of product ranges
declare @selectedproductranges table([key] uniqueidentifier)

-- this is a table containing a selection of customers
declare @selectedcustomers table([key] uniqueidentifier)

declare @low datetime
    , @up datetime

-- TODO: set top query parameters

.

select
         saleshistory.customer_key
         , saleshistory.product_key
         , saleshistory.amount
         , saleshistory.quantity
from
         dbo.products p
         inner join @selectedproductranges productrangeselection 
             on p.product_range_key = productrangeselection.[key]
         inner join @selectedcustomers customerselection on 1 = 1
         inner join 
         dbo.f_sales_history_..snip.._date_range(@low, @up) saleshistory
             on saleshistory.product_key = p.[key]
             and saleshistory.customer_key = customerselection.[key]

我希望样本有意义.

非常感谢你的帮助!

在这种情况下,它是一个"内联表值函数",如果它有用(或视图),优化器只会扩展(不需要)它.

如果外部查询将该函数视为"黑盒子",则最快的方法是比较分析器中SSMS与IO中显示的IO.Profler捕获SSMS没有的"黑匣子"IO.

Adam Mechanic的博客文章(他的书出现在我的抽屉里)