oracle查询资源占用，锁表解锁

1. 先通过top命令查看产用资源较多的spid号

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2.查询当前耗时的会话ID，用户名，sqlID等：

select sid,serial#,machine,username,program,sql_hash_value,sql_id,

  to_char(logon_time,'yyyy/mm/dd hh24:mi:ss') as login_time from v$session

where paddr in (select addr from v$process where spid in ('5648612','256523'));

3. 如果上一步sql_id或者 hash_value不为空，则可用v$sqlarea查出当前正在使用的sql

select sql_text

from v$sqltext_with_newlines

where hash_value = hash_value

order by piece;

也可直接使用:

select a.*,b.SQL_TEXT from (

select sid,serial#,machine,username,program,sql_hash_value,sql_id,

  to_char(logon_time,'yyyy/mm/dd hh24:mi:ss') as login_time from v$session

where paddr in (select addr from v$process where spid in ('23226'))

) a,v$sql b

where a.sql_id  = b.SQL_ID(+)

4.kill占用大资源的session

Alter system kill session 'SID,SERIAL#'

解锁：

1.查询哪些对象被锁：

select object_name,machine,s.sid,s.serial#

from v$locked_object l,dba_objects o ,v$session s

where l.object_id　=　o.object_id and l.session_id=s.sid;

2.下面的语句用来杀死一个进程：

alter system kill session '524,1095'; (其中24,111分别是上面查询出的sid,serial#)

3.再一次查询目前锁定的对象，若发现以上方法不能解除锁定的表，则用以下方法：

3.1 执行下面的语句获得进程（线程）号：

select spid, osuser, s.program

from v$session s,v$process p

where s.paddr=p.addr and s.sid=524 （524是上面的sid）

模拟oracle数据库update锁表现象及处理办法

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

oracle 表锁住了什么原因

在对指定表做append操作，其他再做truncate时候，会产生锁表，如下验证步骤，

1、创建测试表，

create table test_lock(id number, value varchar2(200));

2、执行append语句；并且不做提交，insert /*+append*/ into test_lock values(1,1);

3、再次执行清表语句，truncate table test_lock;报锁表错误，

4、查看锁表语句，发现被锁表，

select b.object_name, t.*

from v$locked_object t, user_objects b

where t.object_id = b.object_id

oracle 表被锁住 怎么解锁

一般先查询并找到被锁定的表，解锁代码如下:

--释放SESSION SQL: 

--alter system kill session 'sid, serial#'; 

ALTER system kill session '23, 1647';

oracle数据库怎么锁表

oracle数据库分行级锁和表级锁。用select * from table-name for update完成行级锁。用delete或update完成表级锁。你锁定的资源 别人会等待你的提交语句或回退语句完成以后再继续进行。