清除SQL Server数据缓存和执行计划缓存,查看执行计划的各种方式对比

清除数据和执行计划缓存：

DBCC DROPCLEANBUFFERS
DBCC FREEPROCCACHE

打开统计数据：

SET STATISTICS IO ON

SET STATISTICS TIME ON

打开执行计划：

SET SHOWPLAN_TEXT ON
SET SHOWPLAN_ALL ON
SET STATISTICS PROFILE ON
SET SHOWPLAN_XML ON
SET STATISTICS PROFILE XML

各选项的区别
	Command	Execute Query?	Include Estimated Row Counts & Stats	Include Actual Row Counts & Stats
Text Plan	SET SHOWPLAN_TEXT ON	No	No	No
	SET SHOWPLAN_ALL ON	No	Yes	No
	SET STATISTICS PROFILE ON	Yes	Yes	Yes
XML Plan	SET SHOWPLAN_XML ON	No	Yes	No
	SET STATISTICS PROFILE XML	Yes	Yes	Yes