My Oracle Support Banner

Tracing Sessions: Waiting On An Enqueue (Doc ID 1400250.1)

Last updated on MARCH 03, 2022

Applies to:

Oracle Database - Standard Edition - Version to [Release 7.3.0 to 11.2]
Oracle Database - Personal Edition - Version to [Release 7.2.3 to 11.2]
Oracle Database - Enterprise Edition - Version to [Release 7.2.3 to 11.2]
Oracle Database Cloud Schema Service - Version N/A and later
Oracle Database Exadata Cloud Machine - Version N/A and later
Information in this document applies to any platform.


NOTE: In the images and/or the document content below, the user information and data used represents fictitious data from the Oracle sample schema(s) or Public Documentation delivered with an Oracle database product. Any similarity to actual persons, living or dead, is purely coincidental and not intended in any manner.

How to monitor and trace locking problems (enqueues).

This bulletin will assist you when:

1. Requiring to figure out if an instance has had locking problems with
enqueues. See section "Has locking been a problem".

2. Are there sessions just now in the instance that are waiting on
enqueues and who are the blockers. See "Is locking a problem just now".

Troubleshooting Steps

To view full details, sign in with your My Oracle Support account.

Don't have a My Oracle Support account? Click to get started!

In this Document
Troubleshooting Steps
 What are locks, enqueues and latches
 Common types of enqueues
 Has locking been a problem
 Is locking a problem currently

My Oracle Support provides customers with access to over a million knowledge articles and a vibrant support community of peers and Oracle experts.