SQL Server 05提供了动态管理视图Dynamic Management Views和函数 Functions,方便了我们对系统运行情况的监控,故障诊断和性能优化.配合Profiler,dashboard一起使用很不错.
使用sys.dm_exec_query_stats和sys.dm_exec_sql_text找到CPU占用率高的语句 这里有篇文章不错/tips/159/7771659.shtml
SELECTTOP100execution_count,
total_logical_reads/execution_countAS[AvgLogicalReads],
total_elapsed_time/execution_countAS[AvgElapsedTime],
db_name(st.dbid)as[databasename],
object_name(st.dbid)as[objectname],
object_name(st.objectid)as[objectname1],
SUBSTRING(st.text,(qs.statement_start_offset/2)+1,
((CASEstatement_end_offsetWHEN-1THENDATALENGTH(st.text)ELSEqs.statement_end_offsetEND-qs.statement_start_offset)
/2)+1)ASstatement_text
FROMsys.dm_exec_query_statsASqsCROSSAPPLYsys.dm_exec_sql_text(qs.sql_handle)ASst
WHEREexecution_count>100
ORDERBY1DESC;
--关于statement_start_offset/2的疑问/u/0308/14/6b6307d1-efea-459c-b3cd-b50c29d3642e.html
IO跟踪
setstatistics io on
go
selecttop1*from sales.customer where customertype <>'S';
CustomerID TerritoryID AccountNumber CustomerType rowguidModifiedDate CustomerID TerritoryID AccountNumber CustomerType rowguidModifiedDate
----------- ----------- ------------- ------------ ------------------------------------ -----------------------
11000 9AW00011000 I477586B3-2977-4E54-B1A8-569AB2C7C4D4 -10-13 11:15:07.263
(1 行受影响)
表 'Customer'。扫描计数 1,逻辑读取 6 次,物理读取 0 次,预读 0 次,lob 逻辑读取 0 次,lob 物理读取 0 次,lob 预读 0 次。
--如果需要清理缓存池DBCC DROPCLEANBUFFER CPU时间
declare@xint;
declare@cpu_startint;
set@x=1;
set@cpu_start=@@cpu_busy;
while@x<10000
set@x=@x+1;
print'ms of cput for loop1:'
+cast ( (@@cpu_busy-@cpu_start) +@@timeticks/1000aschar);
set@cpu_start=@@cpu_busy;
while@x<100000
set@x=@x+1;
print'ms of cput for loop1:' +cast ( (@@cpu_busy-@cpu_start) +@@timeticks/1000aschar);--注意这两个参数@@cpu_busy @@timeticks使用sys.dm_exec_cached_plans和sys.dm_exec_sql_text找到执行最频繁的语句这里有篇文章不错/tips/161/7810661.shtml
当dbid值是32767时,就会出现这种情况。因为数据库的ID号与系统数据库,即所谓的资源库是有联系的。这个资源库不是众所周知,但它却是存在于系统中的一个实际数据库,他的确存在,但你在SQL Server Management Studio中却看不到它。在你的数据文件目录下,有一个以字符串“mssqlsystemreource”开始命名的MDF和LDF文件,那就是资源数据库了
SELECTCASEwhen dbid =32767
then'Resource'
elseDB_NAME(dbid) end[DB_NAME],
OBJECT_SCHEMA_NAME(objectid,dbid) AS[SCHEMA_NAME],
OBJECT_NAME(objectid,dbid)AS[OBJECT_NAME],
SUM(usecounts) AS[Use_Count],
SUM(total_elapsed_time) AS[total_elapsed_time],
SUM(total_elapsed_time) /SUM(usecounts) *1.0AS[avg_elapsed_time],
substring(convert(char(23),DATEADD(ms,sum(total_elapsed_time)/1000,0),121),12,23) AS total_elapsed_time_ms, dbid,
objectid
FROM sys.dm_exec_cached_plans cp
CROSS APPLY sys.dm_exec_sql_text(cp.plan_handle)
JOIN
(SELECTSUM(total_elapsed_time) AS[total_elapsed_time],
plan_handle
FROM sys.dm_exec_query_stats
GROUPBY plan_handle) qs
ON cp.plan_handle = qs.plan_handle
WHERE objtype ='Proc'
ANDUPPER(
-- remove white space first
REPLACE(
REPLACE(
REPLACE(
REPLACE(
REPLACE(
REPLACE(
REPLACE(text,'',''),
'',''),
'',''),
'', ''),
'',''),
'',''),
'','')
)
LIKE'%CREATE PROC%'
GROUPBY dbid, objectid
ORDERBYSUM(total_elapsed_time) /SUM(usecounts) *1.0DESC;
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