模拟oracle数据库update锁表现象及处理办法

jiawang

Session1创建测试表：
SQL> create table test (id number (10) not null , name varchar(20), primary key(id));
Table created.

SQL> desc test;
Name                                      Null?    Type
----------------------------------------- -------- ----------------------------
ID                                        NOT NULL NUMBER(10)
NAME                                               VARCHAR2(20)

SQL> insert into test values(001,'tom');
1 row created.

SQL> insert into test values(002,'lisa');
1 row created.

SQL> insert into test values(003,'joy');
1 row created.

SQL> insert into test values(004,'jia');
1 row created.

查看test表信息
SQL> update test set name='xue' where name='joy';
1 row updated.

SQL> commit;
Commit complete.

SQL> select * from test updata;

        ID NAME
---------- --------------------
         1 tom
         2 lisa
         3 xue
         4 jia

重新打开session 2：
SQL>  select * from test；
        ID NAME
---------- --------------------
         1 tom
         2 lisa
         3 xue
         4 jia

update模拟锁表
SQL> update test set name='da' where name='tom';
1 row updated.
注：不提交

Session2查询：
SQL>  select * from test；
        ID NAME
---------- --------------------
         1 tom
         2 lisa
         3 xue
         4 jia
查看哪个表被锁
SQL> select b.owner,b.object_name,a.session_id,a.locked_mode from v$locked_object a,dba_objects b where b.object_id = a.object_id;
OWNER
------------------------------
OBJECT_NAME
--------------------------------------------------------------------------------
SESSION_ID LOCKED_MODE
---------- -----------
SYS
TEST
        23           3

查看是哪个session引起的
SQL> select b.username,b.sid,b.serial#,logon_time from v$locked_object a,v$session b where a.session_id = b.sid order by b.logon_time;

USERNAME                              SID    SERIAL# LOGON_TIM
------------------------------ ---------- ---------- ---------
SYS                                    23         23 02-JAN-20

杀掉对应进程
SQL> alter system kill session'23,23';
System altered.
其中23为sid,23为serial#.

SQL> select b.owner,b.object_name,a.session_id,a.locked_mode from v$locked_object a,dba_objects b where b.object_id = a.object_id;
no rows selected

SQL> select b.username,b.sid,b.serial#,logon_time from v$locked_object a,v$session b where a.session_id = b.sid order by b.logon_time;
no rows selected

session 1查询：
SQL> select * from test;      
select * from test
*
ERROR at line 1:
ORA-00028: your session has been killed

SQL> select * from test;
select * from test
*
ERROR at line 1:
ORA-01012: not logged on
Process ID: 5366
Session ID: 23 Serial number: 23

重新连接SQL
[oracle@localhost ~]$ sqlplus / as sysdba
SQL*Plus: Release 11.2.0.4.0 Production on Thu Jan 2 11:39:53 2020
Copyright (c) 1982, 2013, Oracle.  All rights reserved.

Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options

SQL> select * from test updata;
        ID NAME
---------- --------------------
         1 tom
         2 lisa
         3 xue
         4 jia