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 







Buffer hit ratio for multiple data buffers

Oracle Database Tips by Donald BurlesonNovember 7, 2015

Question:  I have a KEEP pool defined, plus a db_2k_cache_size, a db_16k_cache_size and a db_32k_cache_size.  I do not see the data buffer hit ratios for multiple data buffer caches in my AWR report.  How do I get the data buffer hit ratio for multiple data buffers

Answer:  The script will display the data buffer hit ratio for all of the data buffer caches when using multiple blocksizes and multiple data caches.

   (1-(physical_reads/ decode(db_block_gets+consistent_gets, 0, .001, db_block_gets+consistent_gets)))*100 buffer_cache_hit_ratio

The following is a sample output from this script to display the buffer hit ratio (BHR) for all 7 data buffer caches. The names of the sized block buffers remain DEFAULT, and the db_block_size column must be selected to differentiate between the buffers.

The sample output shows all 7 data buffers.

----------- ---------- ---------------
DEFAULT     32,767     .97
RECYCLE     16,384     .61
KEEP        16,384    1.00
DEFAULT     16,384     .92
DEFAULT      4,096     .99
DEFAULT      8,192     .98
DEFAULT      2,048     .86

Get the Complete
Oracle SQL Tuning Information 

The landmark book "Advanced Oracle SQL Tuning  The Definitive Reference"  is filled with valuable information on Oracle SQL Tuning. This book includes scripts and tools to hypercharge Oracle 11g performance and you can buy it for 30% off directly from the publisher.



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