Simulation and Problem Analysis of library cache pin in case of a single Oracle instance, oraclepin

Source: Internet
Author: User

Simulation and Problem Analysis of library cache pin in case of a single Oracle instance, oraclepin

Simulation and Analysis of library cache pin problems with a single Oracle instance

Reference:


WAITEVENT: "library cache pin" Reference Note (Doc ID 34579.1)
How to Find the Blocker of the 'library cache pin' in a RAC environment? (Documentation ID 780514.1)

 

Local Environment: Oracle 10.2.0.5 x86-64bit for RHEL5.8 x86-64bit

 

First session:

[Oracle @ localhost ~] $ Sqlplus/as sysdbaSQL * Plus: Release 10.2.0.5.0-Production on Fri Jun 12 17:27:28 2015 Copyright (c) 1982,201 0, Oracle. all Rights Reserved. connected to an idle instance. SQL> startupORACLE instance started. total System Global Area 281018368 bytesFixed Size 2095672 bytesVariable Size 96470472 bytesDatabase Buffers 176160768 bytesRedo Buffers 6291456 bytesDatabase mounted. database opened. SQL> create user lc00%9 identified by aaaaaa; User created. SQL> grant dba to lc0019999; Grant succeeded. SQL> create user lc0029999 identified by aaaaaa; User created. SQL> grant dba to lc0029999; Grant succeeded. SQL> create user lc0039999 identified by aaaaaa; User created. SQL> grant dba to lc0039999; Grant succeeded. SQL> conn lc0019999/aaaaaaConnected. SQL> show userUSER is "lc005o9" SQL> select * from v $ mystat where rownum <2; sid statistic # VALUE ---------- 159 0 1SQL> Create or replace procedure dummy is 2 begin 3 null; 4 end; 5/Procedure created. SQL> Begin 2 Dummy; 3 Dbms_lock.sleep (1000); 4 End; 5/----------> always sleep



Log on to a new session with lc0029999

[Oracle @ localhost ~] $ Sqlplus lc0029999/aaaaaaSQL * Plus: Release 10.2.0.5.0-Production on Fri Jun 12 17:34:04 2015 Copyright (c) 1982,201 0, Oracle. all Rights Reserved. connected to: Oracle Database 10g Enterprise Edition Release 10.2.0.5.0-64bit ProductionWith the Partitioning, OLAP, Data Mining and Real Application Testing optionsSQL> select * from v $ mystat where rownum <2; sid statistic # VALUE ---------- 158 0 1SQL> SQL> alter procedure lc004.7 9.dummy compile; ------------> always hang


 

Start a new session as a sys user

[Oracle @ localhost ~] $ Sqlplus/as sysdbaSQL * Plus: Release 10.2.0.5.0-Production on Fri Jun 12 17:31:33 2015 Copyright (c) 1982,201 0, Oracle. all Rights Reserved. connected to: Oracle Database 10g Enterprise Edition Release 10.2.0.5.0-64bit ProductionWith the Partitioning, OLAP, Data Mining and Real Application Testing optionsSQL> set line 200SQL> select sid, serial #, event from v $ session where event like '% library c Ache pin % '; sid serial # EVENT ---------- ---------------------------------------------------------------- 158 28 library cache pinSQL> select sid, serial #, p1raw, event from v $ session where event like '% library cache pin %'; sid serial # P1RAW EVENT ---------- -------------------- Jun 158 28 Jun 6bff19b0 library cache pinSQL> col owner For a30SQL> col object for a30SQL> SELECT kglnaown "Owner", kglnaobj "Object" 2 FROM x $ kglob 3 WHERE kglhdadr = '2017100006bff19b0' ----> P1RAW value found above. 4; ----> this statement is used to query the object on which the wait event occurs. Owner Object ------------------------------ lc00%9 DUMMYSQL> SQL> SELECT s. sid, kglpnmod "Mode", kglpnreq "Req" 2 FROM x $ kglpn p, v $ session s 3 WHERE p. kglpnuse = s. saddr 4 AND kglpnhdl = 'wait 6bff19b0'; ----> this statement is used to query the waiting sid (REQ> 0) AND blocking sid (Mode> 0) of the event) SID Mode Req ---------- 158 0 3 159 2 0SQL>
 
From WAITEVENT: "library cache pin" Reference Note (Document ID 34579.1) An X request (3) will be blocked by any pins held S mode (2) on the object. an S request (2) will be blocked by any X mode (3) pin held, or may queue behind some other X request.


 

Related Article

Contact Us

The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion; products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the content of the page makes you feel confusing, please write us an email, we will handle the problem within 5 days after receiving your email.

If you find any instances of plagiarism from the community, please send an email to: info-contact@alibabacloud.com and provide relevant evidence. A staff member will contact you within 5 working days.

A Free Trial That Lets You Build Big!

Start building with 50+ products and up to 12 months usage for Elastic Compute Service

  • Sales Support

    1 on 1 presale consultation

  • After-Sales Support

    24/7 Technical Support 6 Free Tickets per Quarter Faster Response

  • Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.