关于死锁的侦测问题

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之前看到过有人写的如何记录下死锁发生时的状况：

--转贴:
MSSQL(查找死锁)：

use master
go
declare @spid int,@bl int
DECLARE s_cur CURSOR FOR
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
OPEN s_cur
FETCH NEXT FROM s_cur INTO @spid,@bl
WHILE @@FETCH_STATUS = 0
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 )
FETCH NEXT FROM s_cur INTO @spid,@bl
end
CLOSE s_cur
DEALLOCATE s_cur




--邹建的
create proc sp_lockinfo
@kill_lock_spid bit=1, --是否杀掉阻塞的进程,1 杀掉, 0 仅显示
@show_spid_if_nolock bit=1, --如果没有阻塞的进程,是否显示正常进程信息,1 显示,0 不显示
@dbname sysname='' --如果为空,则查询所有的库,如果为null,则查询当前库,否则查询指定库
as
set nocount on
declare @count int,@s nvarchar(2000),@dbid int
if @dbname='' set @dbid=db_id() else set @dbid=db_id(@dbname)

select id=identity(int,1,1),标志,
进程ID=spid,线程ID=kpid,块进程ID=blocked,数据库ID=dbid,
数据库名=db_name(dbid),用户ID=uid,用户名=loginame,累计CPU时间=cpu,
登陆时间=login_time,打开事务数=open_tran,进程状态=status,
工作站名=hostname,应用程序名=program_name,工作站进程ID=hostprocess,
域名=nt_domain,网卡地址=net_address
into #t from(
select 标志='阻塞的进程',
spid,kpid,a.blocked,dbid,uid,loginame,cpu,login_time,open_tran,
status,hostname,program_name,hostprocess,nt_domain,net_address,
s1=a.spid,s2=0
from master..sysprocesses a join (
select blocked from master..sysprocesses
where blocked>0
and(@dbid is null or dbid=@dbid)
group by blocked
)b on a.spid=b.blocked
where a.blocked=0
and(@dbid is null or dbid=@dbid)
union all
select '|_牺牲品_>',
spid,kpid,blocked,dbid,uid,loginame,cpu,login_time,open_tran,
status,hostname,program_name,hostprocess,nt_domain,net_address,
s1=blocked,s2=spid
from master..sysprocesses a
where blocked<>0
and(@dbid is null or dbid=@dbid)
)a order by s1,s2

select @count=@@rowcount

if @count=0 and @show_spid_if_nolock=1
begin
insert #t
select 标志='正常的进程',
spid,kpid,blocked,dbid,db_name(dbid),uid,loginame,cpu,login_time,
open_tran,status,hostname,program_name,hostprocess,nt_domain,net_address
from master..sysprocesses
where @dbid is null or dbid=@dbid
order by spid
set @count=@@rowcount
end

if @count>0
begin
create table #t1(id int identity(1,1),a nvarchar(30),b Int,EventInfo nvarchar(255))
declare tb cursor local
for
select N'insert #t1 exec(''dbcc inputbuffer('+rtrim(进程ID)+')'')
if @@rowcount=0 insert #t1(a) values(null)
'+case when @kill_lock_spid=1 and 标志=N'阻塞的进程'
then 'kill '+rtrim(进程ID) else '' end
from #t
open tb
fetch tb into @s
while @@fetch_status=0
begin
exec(@s)
fetch tb into @s
end
close tb
deallocate tb
select a.*,进程的SQL语句=b.EventInfo
from #t a join #t1 b on a.id=b.id
order by a.ID
end
set nocount off
go

我发现原理在于，当发生死锁时，首先从sysprocesses中找出阻塞的spid，然后通过DBCC INPUTBUFFER找到sql语句，这个sql语句是最近一次在该spid上执行的sql语句。
但是，既然这是一个多连接的环境，也可以认为是多线程的环境，所以在死锁的时候获得最近一次的sql语句，这种方法并不可靠，因为导致这个spid的另外一个spid上，此刻可能已经又执行了数条sql语句，获得的那个spid最后的sql语句也就不是我所期望的造成死锁的sql语句。
我的理解正确么？有哪位可以指点一下？

[xiaoku]

不明白o...学习顶。