BC remote Oracle DBA - Call (800) 766-1884  
Oracle Consulting Oracle Training Development

Remote DBA

Remote DBA Plans  

Remote DBA Service

Remote DBA RAC

Remote DBA Oracle Home
Remote DBA Oracle Training
Remote DBA SQL Tuning Consulting
Remote DBA Oracle Tuning Consulting
Remote DBA Data Warehouse Consulting
Remote DBA Oracle Project Management
Remote DBA Oracle Security Assessment
Remote DBA Unix Consulting
Burleson Books
Burleson Articles
Burleson Web Courses
Burleson Qualifications
Oracle Links
Remote DBA Oracle Monitoring
Remote DBA Support Benefits
Remote DBA Plans & Prices
Our Automation Strategy
What We Monitor
Oracle Apps Support
Print Our Brochure
Contact Us (e-mail)
Oracle Job Opportunities
Oracle Consulting Prices





Remote DBA services

Remote DBA Support

Remote DBA RAC

Remote DBA Reasons

Remote Oracle Tuning

Remote DBA Links

Oracle DBA Support

Oracle DBA Forum

Oracle Disaster

Oracle Training

Oracle Tuning

Oracle Training

 Remote DBA SQL Server

Remote MSSQL Consulting

Oracle DBA Hosting

Oracle License Negotiation







  Oracle Tips by Burleson

Prerequisites to Collecting SQL Trace Data

There are a couple prerequisite parameters that must be addressed no matter which method is used for enabling tracing.  Timed statistics must be enabled in order to get timing information about the process. Timed statistics can be enabled at startup using the pfile or spfile.  In the pfile, set the parameter to timed_statistics = TRUE, while the spfile could be updated with the following command: 


In the early days of Oracle, possibly as recently as version 7, using this parameter had a negative impact, reportedly around 10%, on database performance.  However, since version 8 and definitely in 9i and 10g, if there is any performance impact, it is widely believed to not be measurable.  

In spite of this, Metalink documentation still appears to be divided on this issue.  The reference note for this parameter states, “Normally, timed_statistics should be false.”  Meanwhile note 30824.1, states that the small amount of overhead from tuning this tracing on is worth the benefits gained.   

In the face of this ambiguity from Oracle, many Remote DBAs choose to leave this to TRUE on an instance-wide level for most databases.  The exception to this is when a bug is impacting normal operations and cannot be patched. 

It can also be enabled with either an ALTER SYSTEM or ALTER SESSION call at any time for either a specific session or the whole instance.   There are a few ways to accomplish this, but only two ways are shown here. These should work for most installations.

The above book excerpt is from:

Oracle Wait Event Tuning

High Performance with Wait Event Interface Analysis 

ISBN 0-9745993-7-9  

Stephen Andert 


Remote DBA Service

Oracle Tuning Book


Advance SQL Tuning Book 

BC Oracle support

Oracle books by Rampant

Oracle monitoring software







BC Remote Oracle Support

Remote DBA

Remote DBA Services

Copyright © 1996 -  2013 by Burleson. All rights reserved.

Oracle® is the registered trademark of Oracle Corporation.