RE: Locks

From: Steve Adams <steve.adams_at_ixora.com.au>
Date: Thu, 25 May 2000 10:39:06 +1000
Message-Id: <10507.106609@fatcity.com>

Hello Witold,

As explained on page 42 in my book, a waiter can block other requests without yet holding any locks. "For example, if a lock is held in shared mode, and the first waiter requires access to the resource in exclusive mode, then other sessions that require shared access must queue for the resource behind the first waiter, despite the fact that their requests are compatible with the mode in which the resource is currently locked." The utllockt.sql script and most other diagnostic tools ignore this possibility, making it difficult to diagnose. There is a script on my web site called enqueue_locks.sql that will show the order of the waiters, and thus help you to diagnose such situations.

Regards,
Steve Adams

http://www.ixora.com.au/
http://www.oreilly.com/catalog/orinternals/
http://www.christianity.net.au/


-----Original Message-----
From:	Witold Iwaniec [SMTP:wiwaniec_at_novalistech.com]
Sent:	Wednesday, May 24, 2000 11:26 PM
To:	Multiple recipients of list ORACLE-L
Subject:	Locks

Hi all

I am running number of concurrent transactions and run into some locks. It all makes sense and I can find out that a session is locked and waiting. But could I find out which session/user is actually causing the lock?

Regards

Witold

Witold Iwaniec
Senior Software Developer
NovaLIS Technologies
wiwaniec_at_novalistech.com
http://www.novalistech.com

--
Author: Witold Iwaniec
  INET: wiwaniec_at_novalistech.com

Fat City Network Services    -- (858) 538-5051  FAX: (858) 538-5051
San Diego, California        -- Public Internet access / Mailing Lists
--------------------------------------------------------------------
To REMOVE yourself from this mailing list, send an E-Mail message
to: ListGuru_at_fatcity.com (note EXACT spelling of 'ListGuru') and in
the message BODY, include a line containing: UNSUB ORACLE-L
(or the name of mailing list you want to be removed from).  You may
also send the HELP command for other information (like subscribing).

Received on Wed May 24 2000 - 19:39:06 CDT