My Oracle Support Banner

Troubleshooting: High CPU Utilization (Doc ID 164768.1)

Last updated on MARCH 30, 2022

Applies to:

Oracle Database - Enterprise Edition - Version and later
Oracle Database Cloud Schema Service - Version N/A and later
Oracle Database Exadata Express Cloud Service - Version N/A and later
Gen 1 Exadata Cloud at Customer (Oracle Exadata Database Cloud Machine) - Version N/A and later
Oracle Cloud Infrastructure - Database Service - Version N/A and later
Generic UNIX
Generic Windows


The purpose of this document is to help in diagnosing the reason for Oracle related processes consuming high CPU

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
 Prevention of High CPU utilization
 Managing High CPU Usage with Resource Manager
 What to look for when multiple processes are using the CPU intensively
 What to look for when one process is using the CPU intensively
 Which process is hogging the CPU?
 Background Processes
 Job processes (CJQ0, Jn, SNPn)
 Advanced Queuing (AQ, QMN)
 Parallel Query (Pnn)
 Oracle (User) processes
 OS Processes and defunct processes
 Finding High CPU Utilization processes on Windows
 Finding High CPU Utilization processes on Unix
 Find Top Activity and Top CPU Session Using ASH Tab From Grid Control

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