搜索表/索引扫描

Question

有没有人有查询通过SQL2005/2008的计划缓存来识别在其执行计划中有表/索引扫描的查询或存储过程？

Answer 1

Pinal Dave实际上发了一篇关于这篇文章的帖子,并对他原来的文章进行了一些修改(几乎不需要任何改动!)你可以得到正确的答案.如果他有一个帐户,请相信他:)

http://blog.sqlauthority.com/2009/03/17/sql-server-practical-sql-server-xml-part-one-query-plan-cache-and-cost-of-operations-in-the-缓存/

他的查询是:

WITH XMLNAMESPACES(DEFAULT N'http://schemas.microsoft.com/sqlserver/2004/07/showplan'),
CachedPlans
(
ParentOperationID,
OperationID,
PhysicalOperator,
LogicalOperator,
EstimatedCost,
EstimatedIO,
EstimatedCPU,
EstimatedRows,
PlanHandle,
QueryText,
QueryPlan,
CacheObjectType,
ObjectType)
AS
(
SELECT
RelOp.op.value(N'../../@NodeId', N'int') AS ParentOperationID,
RelOp.op.value(N'@NodeId', N'int') AS OperationID,
RelOp.op.value(N'@PhysicalOp', N'varchar(50)') AS PhysicalOperator,
RelOp.op.value(N'@LogicalOp', N'varchar(50)') AS LogicalOperator,
RelOp.op.value(N'@EstimatedTotalSubtreeCost ', N'float') AS EstimatedCost,
RelOp.op.value(N'@EstimateIO', N'float') AS EstimatedIO,
RelOp.op.value(N'@EstimateCPU', N'float') AS EstimatedCPU,
RelOp.op.value(N'@EstimateRows', N'float') AS EstimatedRows,
cp.plan_handle AS PlanHandle,
st.TEXT AS QueryText,
qp.query_plan AS QueryPlan,
cp.cacheobjtype AS CacheObjectType,
cp.objtype AS ObjectType
FROM sys.dm_exec_cached_plans cp
CROSS APPLY sys.dm_exec_sql_text(cp.plan_handle) st
CROSS APPLY sys.dm_exec_query_plan(cp.plan_handle) qp
CROSS APPLY qp.query_plan.nodes(N'//RelOp') RelOp (op)
)
SELECT
PlanHandle,
ParentOperationID,
OperationID,
PhysicalOperator,
LogicalOperator,
QueryText,
CacheObjectType,
ObjectType,
EstimatedCost,
EstimatedIO,
EstimatedCPU,
EstimatedRows
FROM CachedPlans
WHERE CacheObjectType = N'Compiled Plan'

你最想要的是扫描类型(Clustered,Table and Index)

and
(PhysicalOperator = 'Clustered Index Scan' or PhysicalOperator = 'Table Scan' 
or PhysicalOperator = 'Index Scan')

获取计划缓存的基本查询并不难,你可以手动kruft XQuery,但公平地说,Pinal做了很好的版本,所以不要重新发明它.