MSSQ调优所需用的语句
看一下各项指标是否正常,是否有阻塞,这个语句选取了前10个最耗CPU时间的会话语句
SELECT TOP 10
[session_id],
[request_id],
[start_time] AS '开始时间',
[status] AS '状态',
[command] AS '命令',
dest.[text] AS 'sql语句',
DB_NAME([database_id]) AS '数据库名',
[blocking_session_id] AS '正在阻塞其他会话的会话ID',
[wait_type] AS '等待资源类型',
[wait_time] AS '等待时间',
[wait_resource] AS '等待的资源',
[reads] AS '物理读次数',
[writes] AS '写次数',
[logical_reads] AS '逻辑读次数',
[row_count] AS '返回结果行数'
FROM sys.[dm_exec_requests] AS der
CROSS APPLY
sys.[dm_exec_sql_text](der.[sql_handle]) AS dest
WHERE [session_id]>50 AND DB_NAME(der.[database_id])='gposdb'
ORDER BY [cpu_time] DESC
如果SQLSERVER存在要等待的资源,那么执行下面语句就会显示出会话中有多少个worker在等待,如果没有则下面语句运行结果为空。
SELECT TOP 10
[session_id],
[request_id],
[start_time] AS '开始时间',
[status] AS '状态',
[command] AS '命令',
dest.[text] AS 'sql语句',
DB_NAME([database_id]) AS '数据库名',
[blocking_session_id] AS '正在阻塞其他会话的会话ID',
der.[wait_type] AS '等待资源类型',
[wait_time] AS '等待时间',
[wait_resource] AS '等待的资源',
[dows].[waiting_tasks_count] AS '当前正在进行等待的任务数',
[reads] AS '物理读次数',
[writes] AS '写次数',
[logical_reads] AS '逻辑读次数',
[row_count] AS '返回结果行数'
FROM sys.[dm_exec_requests] AS der
INNER JOIN [sys].[dm_os_wait_stats] AS dows
ON der.[wait_type]=[dows].[wait_type]
CROSS APPLY
sys.[dm_exec_sql_text](der.[sql_handle]) AS dest
WHERE [session_id]>50
ORDER BY [cpu_time] DESC
查询CPU占用高的语句
SELECT TOP 10
total_worker_time/execution_count AS avg_cpu_cost, plan_handle,
execution_count,
(SELECT SUBSTRING(text, statement_start_offset/2 + 1,
(CASE WHEN statement_end_offset = -1
THEN LEN(CONVERT(nvarchar(max), text)) * 2
ELSE statement_end_offset
END - statement_start_offset)/2)
FROM sys.dm_exec_sql_text(sql_handle)) AS query_text
FROM sys.dm_exec_query_stats
ORDER BY [avg_cpu_cost] DESC
查询缺失索引
SELECT
DatabaseName = DB_NAME(database_id)
,[Number Indexes Missing] = count(*)
FROM sys.dm_db_missing_index_details
GROUP BY DB_NAME(database_id)
ORDER BY 2 DESC;
SELECT TOP 10
[Total Cost] = ROUND(avg_total_user_cost * avg_user_impact * (user_seeks + user_scans),0)
, avg_user_impact
, TableName = statement
, [EqualityUsage] = equality_columns
, [InequalityUsage] = inequality_columns
, [Include Cloumns] = included_columns
FROM sys.dm_db_missing_index_groups g
INNER JOIN sys.dm_db_missing_index_group_stats s
ON s.group_handle = g.index_group_handle
INNER JOIN sys.dm_db_missing_index_details d
ON d.index_handle = g.index_handle
ORDER BY [Total Cost] DESC;
使用DMV来分析SQL Server启动以来累计使用CPU资源最多的语句。例如下面的语句就可以列出前50名
select
c.last_execution_time,c.execution_count,c.total_logical_reads,c.total_logical_writes,c.total_elapsed_time,c.last_elapsed_time,
q.[text]
from
(select top 50 qs.*
from sys.dm_exec_query_stats qs
order by qs.total_worker_time desc) as c
cross apply sys.dm_exec_sql_text(plan_handle) as q
order by c.total_worker_time desc
go
返回最经常运行的100条语句
SELECT TOP 100 cp.cacheobjtype,cp.usecounts,cp.size_in_bytes,qs.statement_start_offset,qs.statement_end_offset,qt.dbid ,qt.objectid
,SUBSTRING(qt.text,qs.statement_start_offset/2,
(case when qs.statement_end_offset = -1
then len(convert(nvarchar(max), qt.text)) * 2
else qs.statement_end_offset end -qs.statement_start_offset)/2) as statement
FROM sys.dm_exec_query_stats qs
cross apply sys.dm_exec_sql_text(qs.sql_handle) as qt
inner join sys.dm_exec_cached_plans as cp on qs.plan_handle=cp.plan_handle
where cp.plan_handle=qs.plan_handle
and cp.usecounts>4
ORDER BY [dbid],[Usecounts] DESC
返回做IO数目最多的50条语句以及它们的执行计划
SELECT TOP 100 cp.cacheobjtype,cp.usecounts,cp.size_in_bytes,qs.statement_start_offset,qs.statement_end_offset,qt.dbid ,qt.objectid
,SUBSTRING(qt.text,qs.statement_start_offset/2,
(case when qs.statement_end_offset = -1
then len(convert(nvarchar(max), qt.text)) * 2
else qs.statement_end_offset end -qs.statement_start_offset)/2) as statement
FROM sys.dm_exec_query_stats qs
cross apply sys.dm_exec_sql_text(qs.sql_handle) as qt
inner join sys.dm_exec_cached_plans as cp on qs.plan_handle=cp.plan_handle
where cp.plan_handle=qs.plan_handle
and cp.usecounts>4
select top 50
(total_logical_reads/execution_count) as avg_logical_reads,
(total_logical_writes/execution_count) as avg_logical_writes,
(total_physical_reads/execution_count) as avg_phys_reads,
Execution_count,
statement_start_offset as stmt_start_offset, statement_end_offset as stmt_end_offset,
substring(sql_text.text, (statement_start_offset/2),
case
when (statement_end_offset -statement_start_offset)/2 <=0 then 64000
else (statement_end_offset -statement_start_offset)/2 end) as exec_statement, sql_text.text,plan_text.*
from sys.dm_exec_query_stats
cross apply sys.dm_exec_sql_text(sql_handle) as sql_text
cross apply sys.dm_exec_query_plan(plan_handle) as plan_text
order by
(total_logical_reads + total_logical_writes) /Execution_count Desc
计算signal wait占整wait时间的百分比
指令等待 CPU 资源的时间占总时间的百分比。如果超过 25% ,说明 CPU 紧张
select convert(numeric(5,4),sum(signal_wait_time_ms)/sum(wait_time_ms))
from Sys.dm_os_wait_stats -- 计算'Cxpacket'占整wait时间的百分比
-- Cxpacket:Sql Server 在处理一句代价很大的语句,要不就是没有合适的索引或筛选条件没能筛选足够的记录,使得语句要返回大量的结果,当 >5% 说明有问题
declare @Cxpacket bigint
declare @Sumwaits bigint
select @Cxpacket = wait_time_ms
from Sys.dm_os_wait_stats
where wait_type = 'Cxpacket'
select @Sumwaits = sum(wait_time_ms)
from Sys.dm_os_wait_stats
select convert(numeric(5,4),@Cxpacket/@Sumwaits)
查询当前数据库上所有用户表格在Row lock上发生阻塞的频率
declare @dbid int
select @dbid = db_id()
Select dbid=database_id, objectname=object_name(s.object_id)
, indexname=i.name, i.index_id --, partition_number
, row_lock_count, row_lock_wait_count
, [block %]=cast (100.0 * row_lock_wait_count / (1 + row_lock_count) as numeric(15,2))
, row_lock_wait_in_ms
, [avg row lock waits in ms]=cast (1.0 * row_lock_wait_in_ms / (1 + row_lock_wait_count) as numeric(15,2))
from sys.dm_db_index_operational_stats (@dbid, NULL, NULL, NULL) s, sys.indexes i
where objectproperty(s.object_id,'IsUserTable') = 1
and i.object_id = s.object_id
and i.index_id = s.index_id
order by row_lock_wait_count desc
--Begin Index(索引) 分析优化的相关 Sql -- 返回当前数据库所有碎片率大于25%的索引
-- 运行本语句会扫描很多数据页面
-- 避免在系统负载比较高时运行
-- 避免在系统负载比较高时运行
declare @dbid int
select @dbid = db_id()
SELECT o.name as tablename,s.* FROM sys.dm_db_index_physical_stats (@dbid, NULL, NULL, NULL, NULL) s,sys.objects o
where avg_fragmentation_in_percent>25 and o.object_id =s.object_id
order by avg_fragmentation_in_percent desc
GO -- 当前数据库可能缺少的索引
-- 非常好用的 Sql 语句
select d.*
, s.avg_total_user_cost
, s.avg_user_impact
, s.last_user_seek
,s.unique_compiles
from sys.dm_db_missing_index_group_stats s
,sys.dm_db_missing_index_groups g
,sys.dm_db_missing_index_details d
where s.group_handle = g.index_group_handle
and d.index_handle = g.index_handle
order by s.avg_user_impact desc
go -- 自动重建或重新组织索引
-- 比较好用,慎用,特别是对于在线 DB
-- Ensure a USE <databasename> statement has been executed first.
SET NOCOUNT ON;
DECLARE @objectid int;
DECLARE @indexid int;
DECLARE @partitioncount bigint;
DECLARE @schemaname nvarchar(130);
DECLARE @objectname nvarchar(130);
DECLARE @indexname nvarchar(130);
DECLARE @partitionnum bigint;
DECLARE @partitions bigint;
DECLARE @frag float;
DECLARE @command nvarchar(4000);
-- Conditionally select tables and indexes from the sys.dm_db_index_physical_stats function
-- and convert object and index IDs to names.
SELECT
object_id AS objectid,
index_id AS indexid,
partition_number AS partitionnum,
avg_fragmentation_in_percent AS frag
INTO #work_to_do
FROM sys.dm_db_index_physical_stats (DB_ID(), NULL, NULL , NULL, 'LIMITED')
WHERE avg_fragmentation_in_percent > 10.0 AND index_id > 0; -- Declare the cursor for the list of partitions to be processed.
DECLARE partitions CURSOR FOR SELECT * FROM #work_to_do; -- Open the cursor.
OPEN partitions; -- Loop through the partitions.
WHILE (1=1)
BEGIN;
FETCH NEXT
FROM partitions
INTO @objectid, @indexid, @partitionnum, @frag;
IF @@FETCH_STATUS < 0 BREAK;
SELECT @objectname = QUOTENAME(o.name), @schemaname = QUOTENAME(s.name)
FROM sys.objects AS o
JOIN sys.schemas as s ON s.schema_id = o.schema_id
WHERE o.object_id = @objectid;
SELECT @indexname = QUOTENAME(name)
FROM sys.indexes
WHERE object_id = @objectid AND index_id = @indexid;
SELECT @partitioncount = count (*)
FROM sys.partitions
WHERE object_id = @objectid AND index_id = @indexid; -- 30 is an arbitrary decision point at which to switch between reorganizing and rebuilding.
IF @frag < 30.0
SET @command = N'ALTER INDEX ' + @indexname + N' ON ' + @schemaname + N'.' + @objectname + N' REORGANIZE';
IF @frag >= 30.0
SET @command = N'ALTER INDEX ' + @indexname + N' ON ' + @schemaname + N'.' + @objectname + N' REBUILD';
IF @partitioncount > 1
SET @command = @command + N' PARTITION=' + CAST(@partitionnum AS nvarchar(10));
EXEC (@command);
PRINT N'Executed: ' + @command;
END; -- Close and deallocate the cursor.
CLOSE partitions;
DEALLOCATE partitions; -- Drop the temporary table.
DROP TABLE #work_to_do;
GO -- 查看当前数据库索引的使用率
-- 非常的有用
SELECT
object_name(object_id) as table_name,
(
select name
from sys.indexes
where object_id = stats.object_id and index_id = stats.index_id
) as index_name,
*
FROM sys.dm_db_index_usage_stats as stats
WHERE database_id = DB_ID()
order by table_name -- 指定表的索引使用情况
declare @table as nvarchar(100)
set @table = 't_name'; SELECT
(
select name
from sys.indexes
where object_id = stats.object_id and index_id = stats.index_id
) as index_name,
*
FROM sys.dm_db_index_usage_stats as stats
where object_id = object_id(@table)
order by user_seeks, user_scans, user_lookups asc --End Index 分析优化的相关 Sql
MSSQ调优所需用的语句的更多相关文章
- SQL Server调优系列进阶篇 - 查询语句运行几个指标值监测
前言 上一篇我们分析了查询优化器的工作方式,其中包括:查询优化器的详细运行步骤.筛选条件分析.索引项优化等信息. 本篇我们分析在我们运行的过程中几个关键指标值的检测. 通过这些指标值来分析语句的运行问 ...
- SQL Server 调优系列进阶篇 - 查询语句运行几个指标值监测
前言 上一篇我们分析了查询优化器的工作方式,其中包括:查询优化器的详细运行步骤.筛选条件分析.索引项优化等信息. 本篇我们分析在我们运行的过程中几个关键指标值的检测. 通过这些指标值来分析语句的运行问 ...
- Java性能优化权威指南-读书笔记(二)-JVM性能调优-概述
概述:JVM性能调优没有一个非常固定的设置,比如堆大小设置多少,老年代设置多少.而是要根据实际的应用程序的系统需求,实际的活跃内存等确定.正文: JVM调优工作流程 整个调优过程是不断重复的一个迭代, ...
- 如何合理的规划一次jvm性能调优
https://blog.csdn.net/miracle_8/article/details/78347172 摘要: JVM性能调优涉及到方方面面的取舍,往往是牵一发而动全身,需要全盘考虑各方面的 ...
- 如何合理的规划jvm性能调优
JVM性能调优涉及到方方面面的取舍,往往是牵一发而动全身,需要全盘考虑各方面的影响.但也有一些基础的理论和原则,理解这些理论并遵循这些原则会让你的性能调优任务将会更加轻松.为了更好的理解本篇所介绍的内 ...
- Oracle调优之buffer pool相关
一个oracle block与data buffer中的一个buffer对应.用户进程(server process)负责读取磁盘上的block到data buffer cache中,DEWn进程负责 ...
- jvm调优原则
合理规划jvm性能调优 JVM性能调优涉及到方方面面的取舍,往往是牵一发而动全身,需要全盘考虑各方面的影响.但也有一些基础的理论和原则,理解这些理论并遵循这些原则会让你的性能调优任务将会更加轻松.为了 ...
- Hive-常见调优方式 && 两个面试sql
Hive作为大数据领域常用的数据仓库组件,在设计和开发阶段需要注意效率.影响Hive效率的不仅仅是数据量过大:数据倾斜.数据冗余.job或I/O过多.MapReduce分配不合理等因素都对Hive的效 ...
- 【java虚拟机】jvm调优原则
转自:https://www.cnblogs.com/xiaopaipai/p/10522794.html 合理规划jvm性能调优 JVM性能调优涉及到方方面面的取舍,往往是牵一发而动全身,需要全盘考 ...
随机推荐
- BZOJ2818 Gcd
本文版权归ljh2000和博客园共有,欢迎转载,但须保留此声明,并给出原文链接,谢谢合作. 本文作者:ljh2000作者博客:http://www.cnblogs.com/ljh2000-jump/转 ...
- git版本控制?
git是一个分布式的版本控制系统,版本控制系统,类似于保险箱,而我们的代码就是资产:通过对代码的有效管理可以更好的提高我们的生产效率:maven是主要是一个项目构建工具,解决的是我们个人在开发过程中的 ...
- SDL 1.2.15 issue
SDL 1.2.15中,对于X11的函数,默认采用动态加载的方式 但相应的X11函数名在SDL中并没有重新命名(SDL2中都添加了前缀X11_) 这样在SDL与其他库混合静态编译链接时,X11的函数就 ...
- virtual和abstract
virtual和abstract都是用来修饰父类的,通过覆盖父类的定义,让子类重新定义. 共同点:如果用来修饰方法,前面必须添加public,要不然就会出现编译错误:虚拟方法或抽象方法是不能私有的. ...
- RDS MySQL 空间问题的原因和解决
来源:https://help.aliyun.com/knowledge_detail/41739.html RDS MySQL 空间问题的原因和解决 更新时间:2016-07-22 17:20:14 ...
- [Unity] Shader(着色器)输入输出和语义
在Unity5.x后, 已经支持了基于物理的光照模型,也就是常说的次时代引擎所必须具备的功能. 如果在Properties使用2D,CG里要用sampler2D,代表使用的是2维纹理 如果在Prope ...
- win7下安装和使用Windows XP Mode
如果想在电脑中安装多个操作系统有几种方法: 1.安装虚拟机,继而在虚拟机中安装操作系统.虚拟机个数就相当于电脑个数,常用的虚拟机软件有VMVare,VMVare功能齐全,但是安装文件较大. 2.如果你 ...
- R语言爬虫初尝试-基于RVEST包学习
注意:这文章是2月份写的,拉勾网早改版了,代码已经失效了,大家意思意思就好,主要看代码的使用方法吧.. 最近一直在用且有维护的另一个爬虫是KINDLE 特价书爬虫,blog地址见此: http://w ...
- 关于requirejs
24718-12042010 00001h6wzKLpfo3gmjJ8xoTPw5mQvY YA8vwka9tH!vibaUKS4FIDIkUfy!!f 3C"rQCIRbShpSlDcFT ...
- 64位操作系统 通过ODP.NET 访问ORACLE 11g
摘要:64位操作系统部署.NET 程序访问oracle时,无法连接问题.(注意:客户端是64位系统 ,服务端是否64位 还是32位无关.) 1.到oracle 官网搜索相关版本的 ODAC网址: ht ...