干货，DBA日常维护实战常用代码

偷懒，又有几天没有更新了，今天来点干货，自己在优化的时候使用的‘工具’

1、查询数据库表占用的空间

if not exists (select 1 from dbo.sysobjects where id = object_id(N'[dbo].[tablespaceinfo]') and OBJECTPROPERTY(id, N'IsUserTable') = 1)
create table tablespaceinfo --创建结果存储表
(nameinfo NVARCHAR(50) , 
rowsinfo int , reserved NVARCHAR(20) , 
datainfo NVARCHAR(20) , 
index_size NVARCHAR(20) , 
unused NVARCHAR(20) )

delete from tablespaceinfo --清空数据表

declare @tablename NVARCHAR(255) --表名称

declare @cmdsql NVARCHAR(500)

DECLARE Info_cursor CURSOR FOR 
select o.name 
from dbo.sysobjects o where OBJECTPROPERTY(o.id, N'IsTable') = 1 
and o.name not like N'#%%' order by o.name

OPEN Info_cursor

FETCH NEXT FROM Info_cursor 
INTO @tablename 

WHILE @@FETCH_STATUS = 0
BEGIN

if exists (select 1 from dbo.sysobjects where id = object_id(@tablename) and OBJECTPROPERTY(id, N'IsUserTable') = 1)
execute sp_executesql 
N'insert into tablespaceinfo exec sp_spaceused @tbname',
N'@tbname NVARCHAR(255)',
@tbname = @tablename

FETCH NEXT FROM Info_cursor 
INTO @tablename 
END

CLOSE Info_cursor
DEALLOCATE Info_cursor
GO


--itlearner注：显示数据库信息
sp_spaceused @updateusage = 'TRUE' 

--itlearner注：显示表信息
select nameinfo,rowsinfo,reserved=cast(replace(reserved,'KB','') as int)/1000 ,datainfo=cast(cast(replace(datainfo,'KB','') as int)/1000 as NVARCHAR(100))+'MB',
index_size=cast(cast(replace(index_size,'KB','') as int)/1000 as NVARCHAR(100))+'MB',
unused=cast(cast(replace(unused,'KB','') as int)/1000 as NVARCHAR(100))+'MB'
from tablespaceinfo 
order by reserved desc

这段东西主要用于查看数据库中哪些表比较大，在空间优化方面需要做处理。当然现在硬盘巨大情况下偶尔会使用到。

2、查询数据库中使用频率最高的查询

SELECT TOP 20 PERCENT 
CP.usecounts AS [使用次数],
CP.cacheobjtype AS [缓存类型],
CP.objtype AS [对象类型],
ST.text AS [TSQL],
QP.query_plan AS [执行计划],
CP.size_in_bytes AS [执行计划占用空间(Byte)]
FROM sys.dm_exec_cached_plans CP
CROSS APPLY sys.dm_exec_sql_text(plan_handle) ST
CROSS APPLY sys.dm_exec_query_plan(plan_handle) QP
ORDER BY usecounts DESC

对这些数据做优化处理，往往会提高较多的系统性能

3、查找死锁，结束死锁进程及其他相关操作

--查询出来

select    
     request_session_id spid,   
     OBJECT_NAME(resource_associated_entity_id) tableName    
 from    
     sys.dm_tran_locks   
 where    
     resource_type='OBJECT '


--杀死死锁进程

kill spid 

 

 

--另:

exec master.dbo.sp_who_lock --查看当前死锁进程 

exec master.dbo.p_killspid ytsafety--杀掉引起死锁的进程 

 

--sp_who_lock如下： 

SET QUOTED_IDENTIFIER ON 
Go 
 SET ANSI_NULLS ON 
 GO 


 create  procedure sp_who_lock 
 as 
 begin 
 declare @spid int,@bl int, 
 @intTransactionCountOnEntry  int, 
         @intRowcount    int, 
         @intCountProperties   int, 
         @intCounter    int 

create table #tmp_lock_who ( 
 id int identity(1,1), 
 spid smallint, 
 bl smallint) 

IF @@ERROR<>0 RETURN @@ERROR 

insert into #tmp_lock_who(spid,bl) select  0 ,blocked 
    from (select * from sysprocesses where  blocked>0 ) a 
    where not exists(select * from (select * from sysprocesses where  blocked>0 ) b 
    where a.blocked=spid) 
    union select spid,blocked from sysprocesses where  blocked>0 

IF @@ERROR<>0 RETURN @@ERROR 
   
-- 找到临时表的记录数 
select  @intCountProperties = Count(*),@intCounter = 1 
 from #tmp_lock_who 

IF @@ERROR<>0 RETURN @@ERROR 

if @intCountProperties=0 
   select '现在没有阻塞和死锁信息' as message 

-- 循环开始 
while @intCounter <= @intCountProperties 
 begin 
-- 取第一条记录 
  select  @spid = spid,@bl = bl 
   from #tmp_lock_who where Id = @intCounter 
 begin 
   if @spid =0 
             select '引起数据库死锁的是: '+ CAST(@bl AS VARCHAR(10)) + '进程号,其执行的SQL语法如下' 
else 
             select '进程号SPID：'+ CAST(@spid AS VARCHAR(10))+ '被' + '进程号SPID：'+ CAST(@bl AS VARCHAR(10)) +'阻塞,其当前进程执行的SQL语法如下' 
DBCC INPUTBUFFER (@bl ) 
 end 

-- 循环指针下移 
set @intCounter = @intCounter + 1 
 end 

drop table #tmp_lock_who 

return 0 
 end 

 

GO 
 SET QUOTED_IDENTIFIER OFF 
 GO 
 SET ANSI_NULLS ON 
 GO 

 

--p_killspid 如下： 

SET QUOTED_IDENTIFIER ON 
 GO 
 SET ANSI_NULLS ON 
 GO 

 

create  proc p_killspid 
 @dbname varchar(200)    --要关闭进程的数据库名 
as  
     declare @sql  nvarchar(500)  
     declare @spid nvarchar(20) 

    declare #tb cursor for 
         select spid=cast(spid as varchar(20)) from master..sysprocesses where dbid=db_id(@dbname) 
     open #tb 
     fetch next from #tb into @spid 
     while @@fetch_status=0 
     begin  
         exec('kill '+@spid) 
         fetch next from #tb into @spid 
     end  
     close #tb 
     deallocate #tb 


 GO 
 SET QUOTED_IDENTIFIER OFF 
 GO 
 SET ANSI_NULLS ON 
 GO 

SET QUOTED_IDENTIFIER ON 
 GO 
 SET ANSI_NULLS ON 
 GO 

 

ALTER   proc p_killspid 
 @dbname varchar(200)    --要关闭进程的数据库名 
as  
     declare @sql  nvarchar(500)  
     declare @spid nvarchar(20) 

    declare #tb cursor for 
         select spid=cast(spid as varchar(20)) from master..sysprocesses where dbid=db_id(@dbname) 
     open #tb 
     fetch next from #tb into @spid 
     while @@fetch_status=0 
     begin  
         exec('kill '+@spid) 
         fetch next from #tb into @spid 
     end  
     close #tb 
     deallocate #tb 


 GO 
 SET QUOTED_IDENTIFIER OFF 
 GO 
 SET ANSI_NULLS ON 
 GO

这段东西有点多，分几个部分，分别是查找死锁问题，解决死锁问题，解决的过程中记得需要把问题整理下，优化代码或者说顺序，甚至在不必要的地方允许脏读等来解决问题，详细等后面的文章细说

干货，DBA日常维护实战常用代码

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