Call now: 252-767-6166  
Oracle Training Oracle Support Development Oracle Apps

 E-mail Us
 Oracle Articles
New Oracle Articles

 Oracle Training
 Oracle Tips

 Oracle Forum
 Class Catalog

 Remote DBA
 Oracle Tuning
 Emergency 911
 RAC Support
 Apps Support
 Oracle Support

 SQL Tuning

 Oracle UNIX
 Oracle Linux
 Remote s
 Remote plans
 Application Server

 Oracle Forms
 Oracle Portal
 App Upgrades
 SQL Server
 Oracle Concepts
 Software Support

 Remote S


 Consulting Staff
 Consulting Prices
 Help Wanted!


 Oracle Posters
 Oracle Books

 Oracle Scripts

Don Burleson Blog 







orakill tips

Oracle Tips by Burleson Consulting


In Windows, there are a couple of kill utilities: the Oracle-centric "orakill" utility and the Windows taskkillprogram.  If the session cannot be killed more gracefully via alter system kill session, or the instance is inaccessible via SQL, then orakill should be used to terminate the offending session. 


Access to the Windows machine containing the database must be secure to use orakill. Any user with access to the box could access orakill or the Windows Task Manager and damage database processes.


Oracle on Windows is implemented based upon threads rather than processes. So when the Windows Task Manager is viewed, all that will be seen is one ORACLE.EXE for that database instance. The individual threads for the sessions will not be visible since Task Manager only shows the process and number of threads. Look at the next screen snapshot; there are two SQL*Plus sessions connected to the database on this Windows box.


Even though two sqlplus.exe processes can be seen, there is but one oracle.exe process. One would need to dig deeper than the basic Windows task management program to find the Oracle dedicated database server process? thread.


Figure 4.7:  ORACLE.EXE in Windows Task Manager

The DBA could use a utility program, such as the free QuickSlice (qslice.exe) and PStat(pstat.exe) from the Microsoft's Resource Kit, or Process Explorer  (procexp.exe), also from Microsoft.


With tools like these, open the oracle.exe process and investigate into its many threads. However, if one simply selects the 1176 thread using Process Explorer and presses the KILL button, there could be a problem. These tools do not inform Oracle's PMON as to what just occurred, so they do not always make a hanging session and its locks go away.


It still may be necessary to also manually run oradebugwakeup 1 to clear the locks, v$sessionand v$process. Hence, it is advisable to always use the Oracle- provided orakillutility instead. Just be careful, because if the wrong thread, such as a background process, is chosen, then the entire database may crash.


Figure 4.8:  Selecting 1176 Thread in Process Explorer

The Windows command to kill this session with orakill would be as follows:


C:\oracle9i\bin>orakill ORCL92 768


In this example, the Windows thread corresponding to the Oracle session can be killed in the operating system without ever logging into the database. For another example, the Windows command to kill a session would be:


C:\oracle9i\bin>orakill ORCL92 768


In this example, the thread (Oracle session) was killed in the operating system without ever logging into the database. Before killing the session, the DBA may decide to view the SQL being executed by the session. This can be obtained by using the TID above (300) in the following SQL statement:


   b.username, a.sql_text
v$sqltext_with_newlines a, v$session b, v$process c
   c.spid = to_number('300', 'xxx')
   c.addr = b.paddr
   b.sql_address = a.address;  


The orakillcommand is very simple. In fact, it is essentially the exact same syntax as the ALTER SYSTEM KILL SESSION. This means that it accepts two parameters - the SID and v$process.spid - which represents the thread number.


C:\Temp>orakill OR0310 1176


Kill of thread id 1176 in instance OR0310 successfully signaled.


This is an excerpt from the book "Oracle Utilities", and you an get it directly from the publisher for 30%-off at the link.



Oracle Training at Sea
oracle dba poster

Follow us on Twitter 
Oracle performance tuning software 
Oracle Linux poster


Burleson is the American Team

Note: This Oracle documentation was created as a support and Oracle training reference for use by our DBA performance tuning consulting professionals.  Feel free to ask questions on our Oracle forum.

Verify experience! Anyone considering using the services of an Oracle support expert should independently investigate their credentials and experience, and not rely on advertisements and self-proclaimed expertise. All legitimate Oracle experts publish their Oracle qualifications.

Errata?  Oracle technology is changing and we strive to update our BC Oracle support information.  If you find an error or have a suggestion for improving our content, we would appreciate your feedback.  Just  e-mail:  

and include the URL for the page.


Burleson Consulting

The Oracle of Database Support

Oracle Performance Tuning

Remote DBA Services


Copyright © 1996 -  2020

All rights reserved by Burleson

Oracle ® is the registered trademark of Oracle Corporation.