如何获得查询的执行计划？（二）
英文原帖：
http://stackoverflow.com/questions/7359702/how-do-i-obtain-a-query-execution-plan
除了以上回复的全面的答案，有时以编程方式访问执行计划会很有用。示例代码如下：
DECLARE @TraceID INT EXEC StartCapture @@SPID, @TraceID OUTPUT EXEC sp_help 'sys.objects' /*<-- Call your stored proc of interest here.*/ EXEC StopCapture @TraceID
示例StartCapture定义
CREATE PROCEDURE StartCapture @Spid INT, @TraceID INT OUTPUT AS DECLARE @maxfilesize BIGINT = 5 DECLARE @filepath NVARCHAR(200) = N'C:\trace_' + LEFT(NEWID(),36) EXEC sp_trace_create @TraceID OUTPUT, 0, @filepath, @maxfilesize, NULL exec sp_trace_setevent @TraceID, 122, 1, 1 exec sp_trace_setevent @TraceID, 122, 22, 1 exec sp_trace_setevent @TraceID, 122, 34, 1 exec sp_trace_setevent @TraceID, 122, 51, 1 exec sp_trace_setevent @TraceID, 122, 12, 1 -- filter for spid EXEC sp_trace_setfilter @TraceID, 12, 0, 0, @Spid -- start the trace EXEC sp_trace_setstatus @TraceID, 1
示例StopCapture定义
CREATE PROCEDURE StopCapture
@TraceID INT
AS
WITH XMLNAMESPACES ('http://schemas.microsoft.com/sqlserver/2004/07/showplan' as sql),
CTE
as (SELECT CAST(TextData AS VARCHAR(MAX)) AS TextData,
ObjectID,
ObjectName,
EventSequence,
/*costs accumulate up the tree so the MAX should be the root*/
MAX(EstimatedTotalSubtreeCost) AS EstimatedTotalSubtreeCost
FROM fn_trace_getinfo(@TraceID) fn
CROSS APPLY fn_trace_gettable(CAST(value AS NVARCHAR(200)), 1)
CROSS APPLY (SELECT CAST(TextData AS XML) AS xPlan) x
CROSS APPLY (SELECT T.relop.value('@EstimatedTotalSubtreeCost',
'float') AS EstimatedTotalSubtreeCost
FROM xPlan.nodes('//sql:RelOp') T(relop)) ca
WHERE property = 2
AND TextData IS NOT NULL
AND ObjectName not in ( 'StopCapture', 'fn_trace_getinfo' )
GROUP BY CAST(TextData AS VARCHAR(MAX)),
ObjectID,
ObjectName,
EventSequence)
SELECT ObjectName,
SUM(EstimatedTotalSubtreeCost) AS EstimatedTotalSubtreeCost
FROM CTE
GROUP BY ObjectID,
ObjectName
-- Stop the trace
EXEC sp_trace_setstatus @TraceID, 0
-- Close and delete the trace
EXEC sp_trace_setstatus @TraceID, 2
GO