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【用户连接】
1.本地连接
SQL> conn scott/tiger
Connected.
SQL> select sid,server from v$sessionwhere username=‘SCOTT‘;
SID SERVER
---------- ---------
42 DEDICATED
SQL> select sid,server,paddr,processfrom v$session where username=‘SCOTT‘;
SID SERVER PADDR PROCESS
---------- --------- ---------------- ------------------------
42 DEDICATED 000000009188D050 16592
--此处的16592标识进程
SQL> conn scott/tiger
Connected.
SQL> ho ps -ef|grep 16592
oracle 16592 16531 0 21:58 pts/1 00:00:00 sqlplus
oracle 16733 16592 0 22:02 ? 00:00:00 oracleorcl(DESCRIPTION=(LOCAL=YES)(ADDRESS=(PROTOCOL=beq)))
–local=yes标识是本地连接,不经过TCP/IP
oracle 16915 16836 0 22:06 pts/2 00:00:00 /bin/bash -c ps -ef|grep 16592
2.远程连接
SQL> select sid,server,paddr,processfrom v$session where username=‘SCOTT‘;
SID SERVER PADDR PROCESS
---------- --------- ---------------- ------------------------
42 DEDICATED 000000009188D050 17041
SQL> ho ps -ef|grep 17041
oracle 17041 16531 0 22:11 pts/1 00:00:00 sqlplus
oracle 17131 16836 0 22:14 pts/2 00:00:00 /bin/bash -c ps -ef|grep 17041
远程连接用同本地连接相同的查询方法查不到结果,可以用如下查询:
SQL> select spid from v$process whereaddr=‘000000009188D050‘;
SPID
------------------------
17045
SQL> ho ps -ef|grep 17045
oracle 17045 1 0 22:11 ? 00:00:00 oracleorcl (LOCAL=NO)
–local=no 标识远程连接,走TCP/IP
oracle 17180 16836 0 22:15 pts/2 00:00:00 /bin/bash -c ps -ef|grep 17045
3.连接模式
A.专有 每个用户进程与一个服务进程进行连接
适合消耗pga为主业务比如dss、olap、 dba常规管理任务、dg实现同步--dg需要专有连接
SQL> select sid,serial#,server fromv$session where username=‘SCOTT‘;
SID SERIAL# SERVER
---------- ---------- ---------
37 236 DEDICATED
SQL> show parameter dispatchers
NAME TYPE VALUE
----------------------------------------------- ------------------------------
dispatchers string (PROTOCOL=TCP) (SERVICE=orclXDB)
max_dispatchers integer
B.共享 多个用户进程与一个服务器的子进程进行连接
[oracle@oracle ~]$ sqlplusscott/tiger@oracle:1521/orclXDB
SQL> select sid,serial#,server from v$sessionwhere username=‘SCOTT‘;
SID SERIAL# SERVER
---------- ---------- ---------
21 536 DEDICATED
27 1008 SHARED ---shared/none 标识共享连接
SQL> select sid,serial#,server,paddrfrom v$session where username=‘SCOTT‘;
SID SERIAL# SERVER PADDR
---------- ---------- --------- ----------------
27 1008 NONE 0000000091888F50
44 1430 NONE 0000000091888F50
-------注意共享连接不管是多少个,此处的PADDR都是一样的。
SQL> select sid,serial#,server,paddrfrom v$session where username=’SCOTT’;
SID SERIAL# SERVER PADDR
---------- ---------- --------- ----------------
21 536 DEDICATED 0000000091892190
44 1433 DEDICATED 0000000091894210
------注意专有连接不管是多少个,每个PADDR都是不一样的。
一个服务器进程可以服务多个用户进程,反之则不成立。
4.连接----物理方式通过协议进行连接
会话----在连接基础上产生的一些信息,可以有一个、可以有多个、可以没有
连接关闭,会话结束
会话结束,连接不一定关闭
会话1:
[oracle@oracle ~]$sqlplus scott/tiger
SQL> set autot trace stat
会话2:
SQL> select sid,serial#,server,paddrfrom v$session where username=‘SCOTT‘;
SID SERIAL# SERVER PADDR
---------- ---------- --------- ----------------
21 536 DEDICATED 0000000091892190
34 799 DEDICATED 0000000091895250
51 252 DEDICATED 0000000091895250
–--表示在一个连接上产生两个会话
SQL> selectsid,serial#,server,paddr,process from v$session where username=‘SCOTT‘;
SID SERIAL# SERVER PADDR PROCESS
---------- ---------- --------- ---------------- ------------------------
21 536 DEDICATED 0000000091892190 19652
34 799 DEDICATED 0000000091895250 21284
51 252 DEDICATED 0000000091895250 21284
--–注意PROCESS是相同,即为同一个进程
SQL> select spid from v$process whereaddr=‘ 0000000091895250‘;
SPID
------------------------
21287
想要KILL这个会话,可以如下操作:
SQL> alter system kill session ‘51,252‘;
alter system kill session ‘51,252‘
*
ERROR at line 1:
ORA-00031: session marked for kill
可能会出现如上的错误,这虽然能终止该会话,但是不能释放相关资源。
SQL> alter system kill session ‘51,252‘immediate;
System altered.
SQL> selectsid,serial#,server,paddr,process from v$session where username=‘SCOTT‘;
SID SERIAL# SERVER PADDR PROCESS
---------- ---------- --------- ---------------- ------------------------
21 536 DEDICATED 0000000091892190 19652
Kill一个进程只需要执行如下操作:
SQL> selectsid,serial#,server,paddr,process from v$session where username=‘SCOTT‘;
SID SERIAL# SERVER PADDR PROCESS
---------- ---------- ------------------------- ------------------------
21 536 DEDICATED 0000000091892190 19652
27 1094 DEDICATED 000000009188D050 21629
SQL> select spid from v$process whereaddr=‘000000009188D050‘;
SPID
------------------------
21632
SQL> ho kill -9 21632
SQL> select sid,serial#,server,paddr,process from v$session whereusername=‘SCOTT‘;
SID SERIAL# SERVER PADDR PROCESS
---------- ---------- ------------------------- ------------------------
21 536 DEDICATED 0000000091892190 19652
27 1094 DEDICATED 000000009188D050 21629
虽然进程被kill了,但是没有退出去,还是能查到,退出之后就查不到了。
http://docs.oracle.com/cd/E11882_01/server.112/e40540/process.htm#CNCPT9840
【用户连接】