oracle获取当前会话(进程)session id(sid)

 

转帖于：http://www.idb-stock.net/idb/2011/06/23/184.html

 

session id 在一些审计、统计分析中还是非常用的，本文介绍常见的获取oracle session id的方法：

1.从v$mystat视图获取oracle当前会话的session id(sid):

select sid
from v$mystat
where rownum = 1;

select sid
  from v$mystat
 where rownum = 1;

2.用userenv函数获取oracle当前会话的session id(sid):

select sid
from v$session
where audsid=userenv('sessionid');

select sid
from v$session
where audsid=userenv('sessionid');

特别说明：userenv(‘sessionid’)对以sys登录的用户是有限制，我们可以看到所有在主机以sys登录的用户的audsid都是0。

$ sqlplus "/as sysdba" SQL*Plus: Release 9.2.0.7.0 - Production on Thu Jun 23 16:50:13 2011 Copyright (c) 1982, 2002, Oracle Corporation. All rights reserved. Connected to: Oracle9i Enterprise Edition Release 9.2.0.7.0 - 64bit Production With the Partitioning, OLAP and Oracle Data Mining options JServer Release 9.2.0.7.0 - Production SQL> show user USER is "SYS" SQL> select t.SID, 2 t.AUDSID, 3 t.USERNAME 4 from v$session t 5 where t.USERNAME = 'SYS' 6 or t.USERNAME is null 7 ; SID AUDSID USERNAME ---------- ---------- ------------------------------ 1 0 2 0 3 0 4 0 5 0 6 0 7 0 8 0 27 0 SYS 9 rows selected. SQL> select userenv('sessionid') from dual; USERENV('SESSIONID') -------------------- 0

3.oracle 10g 用userenv(‘sid’)获取session id(sid):

--oracle 10g以后可以使用
select userenv('sid') from dual;

--oracle 10g以后可以使用
select userenv('sid') from dual;

4.使用dbms_session.unique_session_id获取oracle当前会话的session id(sid):

dbms_session.unique_session_id总共返回20位，其中前4位为session id，5~8位为serial#，具体示例请参考：统计oracle每个用户的事务数

select
to_number(substrb(dbms_session.unique_session_id,1,4),'xxxx') sid,
to_number(substrb(dbms_session.unique_session_id,5,4),'xxxx') audsid
from dual;

select
to_number(substrb(dbms_session.unique_session_id,1,4),'xxxx') sid,
to_number(substrb(dbms_session.unique_session_id,5,4),'xxxx') audsid
from dual;

SQL> select 2 to_number(substrb(dbms_session.unique_session_id,1,4),'xxxx') sid, 3 to_number(substrb(dbms_session.unique_session_id,5,4),'xxxx') audsid 4 from dual; SID AUDSID ---------- ---------- 27 7651 SQL>