Call now: 252-767-6166  
Oracle Training Oracle Support Development Oracle Apps

 E-mail Us
 Oracle Articles
New Oracle Articles

 Oracle Training
 Oracle Tips

 Oracle Forum
 Class Catalog

 Remote DBA
 Oracle Tuning
 Emergency 911
 RAC Support
 Apps Support
 Oracle Support

 SQL Tuning

 Oracle UNIX
 Oracle Linux
 Remote s
 Remote plans
 Application Server

 Oracle Forms
 Oracle Portal
 App Upgrades
 SQL Server
 Oracle Concepts
 Software Support

 Remote S


 Consulting Staff
 Consulting Prices
 Help Wanted!


 Oracle Posters
 Oracle Books

 Oracle Scripts

Don Burleson Blog 







Dropping and deleting Oracle histograms

Oracle Database Tips by Donald BurlesonOctober 3, 2013

I an running bug testing and I have been advised to run a test of my database without any histograms.  Since you cannot get histograms to be ignored easily, what is the procedure for deleting the column histograms while leaving the table statistics.



Answer:  The obvious way to delete histograms is to re-analyze the tables to not include histograms.  We begin by deleting table statistics for the test.  Maria Colgan offers methods for Oracle 10g and Oracle 11g for deleting histograms from tables

dbms_stats.delete_table_stats(ownname=>'SCOTT', tabname=>'EMP');

In addition, with this syntax we can delete all

exec dbms_stats.delete_column_stats(ownname=>'',tabname=>'',

Next, we have to deal with the automatic statistics collecting job, to stop all automatic statistics collections of histograms until out testing is completed.

dbms_stats.lock_table_stats(ownname=>'SCOTT', tabname=>'EMP');

Now we can run a command to analyze all tables, but without histograms, effectively deleting the histograms from the tables.

This command will allow Oracle to automatically gather histograms on all of the other columns in the table but not on the PROD_ID column. Note you need to set the force parameter to true to override the locked statistics.

dbms_stats.gather_table_stats('SCOTT', 'EMP',
force => true);

Starting in 11g and beyond there is a new method for deleting histograms for a table:

This will  delete the histogram for a column while still leaving behind the base column statistics:

SQL> exec dbms_stats.delete_column_stats(null, '', '', col_stat_type=>'HISTOGRAM');


Oracle Training from Don Burleson 

The best on site "Oracle training classes" are just a phone call away! You can get personalized Oracle training by Donald Burleson, right at your shop!

Oracle training



Burleson is the American Team

Note: This Oracle documentation was created as a support and Oracle training reference for use by our DBA performance tuning consulting professionals.  Feel free to ask questions on our Oracle forum.

Verify experience! Anyone considering using the services of an Oracle support expert should independently investigate their credentials and experience, and not rely on advertisements and self-proclaimed expertise. All legitimate Oracle experts publish their Oracle qualifications.

Errata?  Oracle technology is changing and we strive to update our BC Oracle support information.  If you find an error or have a suggestion for improving our content, we would appreciate your feedback.  Just  e-mail:  

and include the URL for the page.


Burleson Consulting

The Oracle of Database Support

Oracle Performance Tuning

Remote DBA Services


Copyright © 1996 -  2020

All rights reserved by Burleson

Oracle ® is the registered trademark of Oracle Corporation.



Oracle Training at Sea
oracle dba poster

Follow us on Twitter 
Oracle performance tuning software 
Oracle Linux poster