RE: How to simulate latch: cache buffers chains and latch: row cache objects

From: Noveljic Nenad <>
Date: Tue, 27 Aug 2019 05:00:03 +0000
Message-ID: <>

To reproduce a latch at will and hold it for deterministic time period I would set the breakpoint with gdb on a function participating in latch allocation.

To get an idea which functions that might be I’d gather stack traces when the latch event gets written into the 10046 trace files. This is something that can be accomplished with either DTrace or gdb. I described the method with DTrace here:

Best regards,



From: <> On Behalf Of kunwar singh Sent: Montag, 26. August 2019 22:40
To: ORACLE-L <> Subject: How to simulate latch: cache buffers chains and latch: row cache objects

Hi Listers,
Just an academic question.

I am trying to learn about these wait events in detail. Can you please share what how i can reproduce it on a 12.2 or higher DB

i have a test machine with 24 cores and 12.2 DB running on it.


Please consider the environment before printing this e-mail. Bitte denken Sie an die Umwelt, bevor Sie dieses E-Mail drucken.

<html xmlns="">
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<style type="text/css">p { font-family: Arial;font-size:9pt }</style>
<br>Important Notice</br>
<br />

This message is intended only for the individual named. It may contain confidential or privileged information. If you are not the named addressee you should in particular not disseminate, distribute, modify or copy this e-mail. Please notify the sender immediately by e-mail, if you have received this message by mistake and delete it from your system.<br /> Without prejudice to any contractual agreements between you and us which shall prevail in any case, we take it as your authorization to correspond with you by e-mail if you send us messages by e-mail. However, we reserve the right not to execute orders and instructions transmitted by e-mail at any time and without further explanation.<br /> E-mail transmission may not be secure or error-free as information could be intercepted, corrupted, lost, destroyed, arrive late or incomplete. Also processing of incoming e-mails cannot be guaranteed. All liability of Vontobel Holding Ltd. and any of its affiliates (hereinafter collectively referred to as "Vontobel Group") for any damages resulting from e-mail use is excluded. You are advised that urgent and time sensitive messages should not be sent by e-mail and if verification is required please request a printed version.</br> Please note that all e-mail communications to and from the Vontobel Group are subject to electronic storage and review by Vontobel Group. Unless stated to the contrary and without prejudice to any contractual agreements between you and Vontobel Group which shall prevail in any case, e-mail-communication is for informational purposes only and is not intended as an offer or solicitation for the purchase or sale of any financial instrument or as an official confirmation of any transaction.<br /> The legal basis for the processing of your personal data is the legitimate interest to develop a commercial relationship with you, as well as your consent to forward you commercial communications. You can exercise, at any time and under the terms established under current regulation, your rights. If you prefer not to receive any further communications, please contact your client relationship manager if you are a client of Vontobel Group or notify the sender. Please note for an exact reference to the affected group entity the corporate e-mail signature. For further information about data privacy at Vontobel Group please consult <a href=""></a>.<br />

Received on Tue Aug 27 2019 - 07:00:03 CEST

Original text of this message