快速查出Oracle数据库中锁等待的方法(2)
此时,若发现该阻塞其它用户进程的进程是正常操作中,则可通知该用户对其进行提交,从而达到释放锁资源的目的;若为未正常操作,即,其状态为"inactive",且其last_call_et已为较多长时间,则可执行以下语句将该进程进行清除,系统会自动对其进行回滚,从而释放锁住的资源。
alter system kill session 'sid, serial#';
SQL 脚本如下:
set echo off
set feedback off
prompt '删除旧记录.....'
truncate table my_session;
truncate table my_lock;
truncate table my_sqltext;
prompt '获取数据.....'
insert into my_session
select a.username, a.sid, a.serial#,
a.lockwait, a.machine,a.status,
a.last_call_et,a.sql_hash_value,a.program
from v$session a
where nvl(a.username,'NULL')< >'NULL;
insert into my_lock
select id1, kaddr, sid, request,type
from v$lock;
insert into my_sqltext
select hash_value , sql_text
from v$sqltext s, my_session m
where s.hash_value=m.sql_hash_value;
column username format a10
column machine format a15
column last_call_et format 99999 heading "Seconds"
column sid format 9999
prompt "正在等待别人的用户"
select a.sid, a.serial#,
a.machine,a.last_call_et, a.username, b.id1
from my_session a, my_lock b
where a.lockwait = b.kaddr;
prompt "被等待的用户"
select a.sid, a.serial#,
a. machine, a.last_call_et,a.username,
b. b.type,a.status,b.id1
from my_session a, my_lock b
where b.id1 in
(select distinct e.id1
from my_session d, my_lock e
where d.lockwait = e.kaddr)
and a.sid = b.sid
and b.request=0;
prompt "查出其 sql "
select a.username, a.sid, a.serial#,
b.id1, b.type, c.sql_text
from my_session a, my_lock b, my_sqltext c
where b.id1 in
(select distinct e.id1
from my_session d, my_lock e
where d.lockwait = e.kaddr)
and a.sid = b.sid
and b.request=0
and c.hash_value =a.sql_hash_value;
以上思路也可用于其它大型数据库系统如 Informix, Sybase,DB2中。通过使用该脚本,可以极大地提高获取系统中当前锁等待的情况,从而及时解决数据库应用系统中的锁等待问题。而且,由于实际上已取出其 program 名及相应的 sql 语句,故可以在事后将其记录下来,交给其开发人员进行分析并从根本上得到解决。



