Common Trouble Solution--处理引…

处理引起等待的sql 语句
1情景描述：在数据库中更新一条数据时，等待很长时间度不会执行结束。
for example：sql>update emp set ename='zhangsan' where empno='111';

2.在数据库中查询哪些会话等待了<1>的sql语句：

sql>select sid,username,blocking_session,
<wbr><wbr> blocking_session_status,blocking_instance<br><wbr><wbr> from v$session where username='xxxx';<br><br><br><br><br> 3.进一步查询是哪个sid的会话导致了&lt;1&gt;会话不能执行：<br><br> sql&gt;select sid,username,blocking_session,event,wait_time<br><wbr><wbr> from v$session where username='xxxx';<br><br> 4.根据sid查询该会话的具体sql语句<br> sql&gt;select sql_text<br><wbr><wbr><wbr> from v$session a ,v$sqltext_with_newlines b<br><wbr><wbr><wbr><wbr> where<br><wbr><wbr><wbr> DECODE (a.sql_hash_value,0 ,prev_hash_value,sql_hash_value)= b.hash_value <wbr><br><wbr><wbr><wbr> and a.sid=&amp;sid order by piece;<br><br> 5.查看数据库中等待的sid,serial#的会话：<br> sql&gt;select t2.username,t2.sid,t2.serial#,t2.logon_time<br><wbr><wbr><wbr> from v$locked_object t1,v$session t2<br><wbr><wbr><wbr> where t1.session_id=t2.sid order by t2.logon_time;<br><br> 6.干掉最早没有提交的sql语句；<br><wbr>sql&gt;alter system kill session '513,4';<br><br></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr></wbr>