如何查看SQL Server 2008中缓存在内存中的内容？

Question

有没有办法找出SQL Server 2008 R2中缓存的内容？我找到了这篇不错的文章：http://blog.sqlauthority.com/2010/06/17/sql-server-data-pages-in-buffer-pool-data-stored-in-memory-cache。然而，我想知道每个表和索引存储了多少数据（以百分比和KB表示）。有没有简单的方法来获取这样的数据？

- Ondra Peterka

Answer 1

你可以使用以下查询语句找到缓冲池（数据缓存）中存储的内容： 从这里：

select
       count(*)as cached_pages_count,
       obj.name as objectname,
       ind.name as indexname,
       obj.index_id as indexid
from sys.dm_os_buffer_descriptors as bd
    inner join
    (
        select       object_id as objectid,
                           object_name(object_id) as name,
                           index_id,allocation_unit_id
        from sys.allocation_units as au
            inner join sys.partitions as p
                on au.container_id = p.hobt_id
                    and (au.type = 1 or au.type = 3)
        union all
        select       object_id as objectid,
                           object_name(object_id) as name,
                           index_id,allocation_unit_id
        from sys.allocation_units as au
            inner join sys.partitions as p
                on au.container_id = p.partition_id
                    and au.type = 2
    ) as obj
        on bd.allocation_unit_id = obj.allocation_unit_id
left outer join sys.indexes ind 
  on  obj.objectid = ind.object_id
 and  obj.index_id = ind.index_id
where bd.database_id = db_id()
  and bd.page_type in ('data_page', 'index_page')
group by obj.name, ind.name, obj.index_id
order by cached_pages_count desc

优秀的参考资料：Inside the Storage Engine: What’s in the buffer pool? 作者：Paul Randal。

- Kin Shah

Answer 2

你可以使用动态管理视图列出当前缓存的页面，并通过数据库ID进行过滤。

   select top 100 * from sys.dm_os_buffer_descriptors

然后你可以使用DBCC PAGE命令来列出一个对象的页面。很好的参考：http://www.mssqltips.com/sqlservertip/1578/using-dbcc-page-to-examine-sql-server-table-and-index-data/ 不过，将结果组合起来将取决于你，而且这似乎不是一项容易的任务：）。当你找到有效的方法时，请告诉我们。

- frikozoid

Answer 3

尝试这个SQL查询：

select count(*)*8/1024 AS 'Cached Size (MB)'        
,case database_id                
when 32767 then 'ResourceDB'                
else db_name(database_id)                
end as 'Database'
from sys.dm_os_buffer_descriptors
where page_type in
(
'INDEX_PAGE'
,'DATA_PAGE'
)
group by db_name(database_id), database_id
order by 'Cached Size (MB)' desc

- Tanmay Nehete