---超过锁请求

http://blog.sina.com.cn/s/blog_7fb3b1840100u4dj.html

1、查询造成死锁的SQL语句

当SQL数据库的监控报警显示死锁进程数过多时，首先应该找出造成死锁的SQL语句是什么，打开“查询分析器”，将如下的存储过程输入到文本框中，检查语法，然后运行：

use master
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 ‘现在没有阻塞信息‘ as message
--循环开始
while @intCounter<=@intCountProperties
begin
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，其执行的SQL语法如下‘
DBCC inputbuffer(@bl)
end
set @intCounter=@intCounter+1
end
drop table #tmp_lock_who
return 0
end
运行完毕，输入exec sp_who_lock 执行存储过程，这时候就可以明确的找出哪个SQL语句造成的死锁和阻塞。

2、杀死锁和进程
我们找出了引起死锁的语句，那么如何去手动的杀死进程和锁？最简单的办法，重新启动服务。但是这里要介绍一个存储过程，通过显式的调用，可以杀死进程和锁。

use master
go

if exists (select * from dbo.sysobjects where id = object_id(N‘[dbo].[p_killspid]‘) and OBJECTPROPERTY(id, N‘IsProcedure‘) = 1)
drop procedure [dbo].[p_killspid]
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

--用法
exec p_killspid ‘newdbpy‘

3、查看锁信息

如何查看系统中所有锁的详细信息？在企业管理管理器中，我们可以看到一些进程和锁的信息，这里介绍另外一种方法。

--查看锁信息
create table #t(req_spid int,obj_name sysname)

declare @s nvarchar(4000)
,@rid int,@dbname sysname,@id int,@objname sysname

declare tb cursor for
select distinct req_spid,dbname=db_name(rsc_dbid),rsc_objid
from master..syslockinfo where rsc_type in(4,5)
open tb
fetch next from tb into @rid,@dbname,@id
while @@fetch_status=0
begin
set @s=‘select @objname=name from [‘+@dbname+‘]..sysobjects where id=@id‘
exec sp_executesql @s,N‘@objname sysname out,@id int‘,@objname out,@id
insert into #t values(@rid,@objname)
fetch next from tb into @rid,@dbname,@id
end
close tb
deallocate tb

select 进程id=a.req_spid
,数据库=db_name(rsc_dbid)
,类型=case rsc_type when 1 then ‘NULL 资源（未使用）‘
when 2 then ‘数据库‘
when 3 then ‘文件‘
when 4 then ‘索引‘
when 5 then ‘表‘
when 6 then ‘页‘
when 7 then ‘键‘
when 8 then ‘扩展盘区‘
when 9 then ‘RID（行 ID)‘
when 10 then ‘应用程序‘
end
,对象id=rsc_objid
,对象名=b.obj_name
,rsc_indid
from master..syslockinfo a left join #t b on a.req_spid=b.req_spid

go
drop table #t

SQL超过锁请求