oracle 游标泄露问题查找

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游标会占用系统资源，oracle中游标分配在shared pool内存池，用完了连接(connection)、语句(statement,preparedStatement)和结果集(resultSet)一定要记得释放，不然系统打开游标会持续上升，直到达到系统设置的阈值，无法获取游标的事务就会失败。

查看系统配置的最大打开游标数量和当前已打开游标数量
[sql]
sql> select (select count(*) from V$OPEN_CURSOR) as opened_cursors,
(select value from v$parameter where name=’open_cursors’) as max_cursors from dual;
OPENED_CURSORS MAX_CURSORS

1362 65535
[/sql]

查询会话打开的游标

[sql]
sql> select s.sid, s.username, s.osuser,s.machine, a.value
from v$sesstat a, v$statname b, v$session s
where a.statistic# = b.statistic# and s.sid=a.sid and b.name = ‘opened cursors current’ and s.username is not null
order by a.value desc;
SID USERNAME OSUSER MACHINE VALUE

405 TT NETWORK?SERVICE WORKGROUP\VIRT-APP-EXTERN 51
466 TT NETWORK?SERVICE WORKGROUP\VIRT-APP 49
491 TT Administrator WORKGROUP\VIRT-APP 13
422 TT Administrator WORKGROUP\VIRT-APP 11
475 TT Administrator WORKGROUP\VIRT-APP 10
……
[/sql]
或者
[sql]
sql> select o.sid, s.username, s.osuser, s.machine, count(*) num
from v$open_cursor o, v$session s
where o.sid = s.sid
group by o.sid,s.username, s.osuser, s.machine
order by num desc;
SID USERNAME OSUSER MACHINE NUM

464 TT NETWORK?SERVICE WORKGROUP\VIRT-APP-EXTERN 34
471 TT NETWORK?SERVICE WORKGROUP\VIRT-APP-EXTERN 30
475 TT Administrator WORKGROUP\VIRT-APP 28
491 TT Administrator WORKGROUP\VIRT-APP 27
……
[/sql]

查询会话执行的sql语句

[sql]
sql> select sid, sql_text, count(sql_text) as num
from v$open_cursor
group by sid, sql_text having count(sql_text)>5
order by num desc;
SID SQL_TEXT NUM

464 select b.*,bb.buildno,bb.BUILDNAME from bldroom b join build 40
464 select t2.businessname,t3.firstname,t1.opion,t1.receivedatet 36
464 select distinct t2.certid,t2.certno from rightcertroom t1 jo 34
……
[/sql]

或者更直接的查询每个sql语句打开的游标数量
[sql]
sql> select s.sid, s.osuser,s.machine, o.sql_text, count(o.sql_text) as num
from v$open_cursor o
join v$session s on o.sid=s.sid
group by s.sid, s.osuser,s.machine,o.sql_text having count(o.sql_text)>50
order by num desc;
SID OSUSER MACHINE SQL_TEXT NUM

464 tomcat8 clean select t2.businessname,t3.firstname,t1.opion,t1.receivedatet 35
464 tomcat8 clean select b.*,bb.buildno,bb.BUILDNAME from bldroom b join build 34
464 tomcat8 clean select distinct t2.certid,t2.certno from rightcertroom t1 jo 28
……
[/sql]

找到对应的SQL语句就可以审计对应的代码，查找资源泄露的情况。

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[erq]