sql server中,如果想知道有哪些语句是执行效率不高的,应该如何查看呢?下面就将为您介绍sql server中如何查看执行效率不高的语句,供您参考。
1.找出执行时间最长的10条SQL(适用于SQL SERVER 2005及其以上版本)
Sql代码
SELECT top 10 (total_elapsed_time / execution_count)/1000 N'平均时间ms' ,total_elapsed_time/1000 N'总花费时间ms' ,total_worker_time/1000 N'所用的CPU总时间ms' ,total_physical_reads N'物理读取总次数' ,total_logical_reads/execution_count N'每次逻辑读次数' ,total_logical_reads N'逻辑读取总次数' ,total_logical_writes N'逻辑写入总次数' ,execution_count N'执行次数' ,creation_time N'语句编译时间' ,last_execution_time N'上次执行时间' ,SUBSTRING( st.text, (qs.statement_start_offset/2) + 1, ( (CASE statement_end_offset WHEN -1 THEN DATALENGTH(st.text) ELSE qs.statement_end_offset END - qs.statement_start_offset)/2 ) + 1 ) N'执行语句' ,qp.query_plan FROM sys.dm_exec_query_stats AS qs CROSS APPLY sys.dm_exec_sql_text(qs.sql_handle) st CROSS APPLY sys.dm_exec_query_plan(qs.plan_handle) qp WHERE SUBSTRING( st.text, (qs.statement_start_offset/2) + 1, ( (CASE statement_end_offset WHEN -1 THEN DATALENGTH(st.text) ELSE qs.statement_end_offset END - qs.statement_start_offset)/2 ) + 1 ) not like '%fetch%' ORDER BY total_elapsed_time / execution_count DESC; 如果想对SQL作筛选,可将 not like '%fetch%' 换成 like '%user%'就可以找出SQL语句中含有user关键字的SQL
2 找出执行最慢的SQL语句(适用于SQL SERVER 2005及其以上版本)
Sql代码
SELECT (total_elapsed_time / execution_count)/1000 N'平均时间ms' ,total_elapsed_time/1000 N'总花费时间ms' ,total_worker_time/1000 N'所用的CPU总时间ms' ,total_physical_reads N'物理读取总次数' ,total_logical_reads/execution_count N'每次逻辑读次数' ,total_logical_reads N'逻辑读取总次数' ,total_logical_writes N'逻辑写入总次数' ,execution_count N'执行次数' ,SUBSTRING(st.text, (qs.statement_start_offset/2) + 1 ,((CASE statement_end_offset WHEN -1 THEN DATALENGTH(st.text) ELSE qs.statement_end_offset END - qs.statement_start_offset)/2) + 1) N'执行语句' ,creation_time N'语句编译时间' ,last_execution_time N'上次执行时间' FROM sys.dm_exec_query_stats AS qs CROSS APPLY sys.dm_exec_sql_text(qs.sql_handle) st WHERE SUBSTRING(st.text, (qs.statement_start_offset/2) + 1, ((CASE statement_end_offset WHEN -1 THEN DATALENGTH(st.text) ELSE qs.statement_end_offset END - qs.statement_start_offset)/2) + 1) not like 'fetch%' ORDER BY total_elapsed_time / execution_count DESC;
3 找出最耗时的前N条T-SQL语句 (适用于SQL SERVER 2005及其以上版本)
Sql代码
--给N赋初值为30 declare @n int set @n=30 ;with maco as ( select top (@n) plan_handle, sum(total_worker_time) as total_worker_time , sum(execution_count) as execution_count , count(1) as sql_count from sys.dm_exec_query_stats group by plan_handle order by sum(total_worker_time) desc ) select t.text , a.total_worker_time , a.execution_count , a.sql_count from maco a cross apply sys.dm_exec_sql_text(plan_handle) t /* 结果格式如下 text total_worker_time execution_count sql_count -------- ------------------ ----------------- --------- 内容略 */
4 平均耗CPU最多的前个SQL (SQL SERVER 2005或以上版本)
Sql代码
SELECT TOP 5 total_worker_time / execution_count AS [Avg CPU Time], SUBSTRING(st.text, (qs.statement_start_offset/2)+1, ((CASE qs.statement_end_offset WHEN -1 THEN DATALENGTH(st.text) ELSE qs.statement_end_offset END - qs.statement_start_offset)/2) + 1) AS statement_text FROM sys.dm_exec_query_stats AS qs CROSS APPLY sys.dm_exec_sql_text(qs.sql_handle) AS st ORDER BY total_worker_time/execution_count DESC
5 平均耗CPU最多的前个SQL (SQL SERVER 2008或以上版本)
Sql代码
SELECT TOP 20 total_worker_time/1000 AS [总消耗CPU 时间(ms)],execution_count [运行次数], qs.total_worker_time/qs.execution_count/1000 AS [平均消耗CPU 时间(ms)], last_execution_time AS [最后一次执行时间],min_worker_time /1000 AS [最小执行时间(ms)], max_worker_time /1000 AS [最大执行时间(ms)], SUBSTRING(qt.text,qs.statement_start_offset/2+1, (CASE WHEN qs.statement_end_offset = -1 THEN DATALENGTH(qt.text) ELSE qs.statement_end_offset END -qs.statement_start_offset)/2 + 1) AS [使用CPU的语法], qt.text [完整语法], qt.dbid, dbname=db_name(qt.dbid), qt.objectid,object_name(qt.objectid,qt.dbid) ObjectName FROM sys.dm_exec_query_stats qs WITH(nolock) CROSS apply sys.dm_exec_sql_text(qs.sql_handle) AS qt WHERE execution_count>1 ORDER BY (qs.total_worker_time/qs.execution_count/1000) DESC
6 总耗CPU最多的前个SQL (SQL SERVER 2008或以上版本)
Sql代码
SELECT TOP 20 total_worker_time/1000 AS [总消耗CPU 时间(ms)],execution_count [运行次数], qs.total_worker_time/qs.execution_count/1000 AS [平均消耗CPU 时间(ms)], last_execution_time AS [最后一次执行时间],max_worker_time /1000 AS [最大执行时间(ms)], SUBSTRING(qt.text,qs.statement_start_offset/2+1, (CASE WHEN qs.statement_end_offset = -1 THEN DATALENGTH(qt.text) ELSE qs.statement_end_offset END -qs.statement_start_offset)/2 + 1) AS [使用CPU的语法], qt.text [完整语法], qt.dbid, dbname=db_name(qt.dbid), qt.objectid,object_name(qt.objectid,qt.dbid) ObjectName FROM sys.dm_exec_query_stats qs WITH(nolock) CROSS apply sys.dm_exec_sql_text(qs.sql_handle) AS qt WHERE execution_count>1 ORDER BY total_worker_time DESC
标签:qs,text,SQL,SQLServer,offset,最耗,statement,time,total From: https://www.cnblogs.com/OpenCoder/p/18294996