– 查询SqlServer总体的内存使用情况
select type
, sum(virtual_memory_reserved_kb) VM_Reserved
, sum(virtual_memory_committed_kb) VM_Commited
, sum(awe_allocated_kb) AWE_Allocated
, sum(shared_memory_reserved_kb) Shared_Reserved
, sum(shared_memory_committed_kb) Shared_Commited
–, sum(single_pages_kb) –SQL2005、2008
–, sum(multi_pages_kb) –SQL2005、2008
from sys.dm_os_memory_clerks
group by type
order by type

– 查询当前数据库缓存的所有数据页面，哪些数据表，缓存的数据页面数量
– 从这些信息可以看出，系统经常要访问的都是哪些表，有多大？
select p.object_id, object_name=object_name(p.object_id), p.index_id, buffer_pages=count(*)
from sys.allocation_units a,
sys.dm_os_buffer_descriptors b,
sys.partitions p
where a.allocation_unit_id=b.allocation_unit_id
and a.container_id=p.hobt_id
and b.database_id=db_id()
group by p.object_id,p.index_id
order by buffer_pages desc

– 查询缓存的各类执行计划，及分别占了多少内存
– 可以对比动态查询与参数化SQL（预定义语句）的缓存量
select cacheobjtype
, objtype
, sum(cast(size_in_bytes as bigint))/1024 as size_in_kb
, count(bucketid) as cache_count
from sys.dm_exec_cached_plans
group by cacheobjtype, objtype
order by cacheobjtype, objtype

– 查询缓存中具体的执行计划，及对应的SQL
– 将此结果按照数据表或SQL进行统计，可以作为基线，调整索引时考虑
– 查询结果会很大，注意将结果集输出到表或文件中
SELECT usecounts ,
refcounts ,
size_in_bytes ,
cacheobjtype ,
objtype ,
TEXT
FROM sys.dm_exec_cached_plans cp
CROSS APPLY sys.dm_exec_sql_text(plan_handle)
ORDER BY objtype DESC ;
GO