1. Find out the 10 SQL with the longest execution time (applicable to SQL SERVER 2005 and above)
SELECT top 10
(total_elapsed_time / execution_count)/1000 N 'average time ms'
,total_elapsed_time/1000 N'total time spent in ms'
,total_worker_time/1000 N'total CPU time used ms'
,total_physical_reads N 'total number of physical reads'
,total_logical_reads/execution_count N'number of logical reads per time'
,total_logical_reads N 'total number of logical reads'
,total_logical_writes N'total number of logical writes'
,execution_count N'execution times'
,creation_time N'statement compile time'
,last_execution_time N'last execution time'
,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 'execute statement'
,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;
If you want to filter on SQL, you can use
Not like '%fetch%' can be replaced by like '%user%' to find the SQL containing the user keyword in the SQL statement
2 Find out the slowest executing SQL statement (applicable to SQL SERVER 2005 and above)
SELECT
(total_elapsed_time / execution_count)/1000 N 'average time ms'
,total_elapsed_time/1000 N'total time spent in ms'
,total_worker_time/1000 N'total CPU time used ms'
,total_physical_reads N 'total number of physical reads'
,total_logical_reads/execution_count N'number of logical reads per time'
,total_logical_reads N 'total number of logical reads'
,total_logical_writes N'total number of logical writes'
,execution_count N'execution times'
,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'execute statement'
,creation_time N'statement compile time'
,last_execution_time N'last execution time'
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 Find the most time-consuming top N T-SQL statements (applicable to SQL SERVER 2005 and above)
-- Assign an initial value of 30 to N
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
/* The result format is as follows
text total_worker_time execution_count sql_count
-------- ------------------ ----------------- ---------
The content is omitted
*/
4 Top SQL with the most average CPU consumption (SQL SERVER 2005 or above)
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 Top SQL that consumes the most CPU on average (SQL SERVER 2008 or above)
SELECT TOP 20
total_worker_time/1000 AS [total CPU consumption (ms)], execution_count [run times],
qs.total_worker_time/qs.execution_count/1000 AS [average CPU time (ms)],
last_execution_time AS [last execution time], min_worker_time /1000 AS [minimum execution time (ms)],
max_worker_time /1000 AS [Maximum execution time (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 [using CPU syntax], qt.text [full syntax],
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 Top SQL with the most CPU consumption (SQL SERVER 2008 or above)
SELECT TOP 20
total_worker_time/1000 AS [total CPU consumption (ms)], execution_count [run times],
qs.total_worker_time/qs.execution_count/1000 AS [average CPU time (ms)],
last_execution_time AS [last execution time], max_worker_time /1000 AS [maximum execution time (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 [using CPU syntax], qt.text [full syntax],
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