降低逻辑读取

Question

我正在使用 stackoverflow2013 数据库，我的查询是

select p.CreationDate, p.title,
c.Text,
c.Score
from comments c join posts p on c.PostId = p.id
where p.CreationDate between ‘2008-08-29 00:00:00’ and ‘2008-09-02 23:59:58’ order by c.score desc

在创建索引之前，我得到了下面 - 执行时间是 18 分 26 秒

    (2055 rows affected)

Table ‘Worktable’. Scan count 0, logical reads 0, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.

Table ‘Workfile’. Scan count 0, logical reads 0, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.

Table ‘Comments’. Scan count 1, logical reads 1028410, physical reads 4, read-ahead reads 1027512, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.

Table ‘Posts’. Scan count 1, logical reads 4184557, physical reads 0, read-ahead reads 4178310, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.

然后我创建了以下索引

create index forcomments on dbo.comments(postid asc ,  Score desc) include (text)
create index forposts on dbo.posts(creationdate asc) include (title)

创建后，查询的性能是惊人的。现在总执行时间为 0 秒。

(2055 rows affected)
Table 'Worktable'. Scan count 0, logical reads 0, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.
Table 'Comments'. Scan count 4536, logical reads 19562, physical reads 0, read-ahead reads 1, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.
Table 'Posts'. Scan count 1, logical reads 26, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0.

我想问我们如何才能使逻辑读取比我们更低 已经有了？

几点 - 统计数据是最新的，在执行计划分析中没有观察到错误的基数。

Answer 1

我想问一下，我们如何才能使逻辑读取比我们现有的更低？

唯一的方法是实现连接的索引视图。