查看SQLServer各种缓存的情况

查看页面缓存：

SELECT * FROM sys.dm_os_buffer_descriptors

清除页面缓存：

CHECKPOINT
DBCC DROPCLEANBUFFERS

查看执行计划缓存：

SELECT * FROM sys.dm_exec_cached_plans

清除执行计划缓存：

DBCC FREEPROCCACHE 或者 DBCC FREESYSTEMCACHE('ALL')

综合应用：

SELECT * FROM (SELECT database_id,obj.name, i.name AS IndexName,page_type,count(*) AS cached_pages_count
FROM sys.dm_os_buffer_descriptors AS bd 
    INNER JOIN 
    (
        SELECT p.object_id, object_name(p.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 
            INNER JOIN sys.objects as o
            ON p.object_id = o.object_id
            WHERE (au.type = 1 OR au.type = 3) and o.type in ('U','V')
        UNION ALL
        SELECT p.object_id, object_name(p.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 
            INNER JOIN sys.objects AS o
            ON p.object_id = o.object_id
            WHERE au.type= 2 and o.type in ('U','V')
    ) AS obj ON bd.allocation_unit_id = obj.allocation_unit_id
    LEFT JOIN sysindexes i ON obj.object_id = i.id AND obj.index_id = i.indid
GROUP BY database_id,page_type,obj.name, index_id, i.name) AS c 
--WHERE database_id = db_id()
ORDER BY database_id,name,IndexName,page_type,cached_pages_count DESC;