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 









Oracle RAC performance in STATSPACK & AWR reports

Oracle Database Tips by Donald Burleson

This excellent presentation  on RAC testing by Plamen Zyumbyulev shows how to interpret Oracle Real application clusters (RAC performance via STATSPACK and AWR reports:

Top 5 Timed Events
~~~~~~~~~~~~~~~~~~                                                % Total
Event                                          Waits    Time (s) Ela Time
--------------------------------------- ------------ ----------- --------
global cache cr request                       34,568         958    31.44
buffer busy global CR                          6,513         620    20.35
db file sequential read                       64,214         455    14.92
latch free                                    13,542         453    14.88
buffer busy waits                             10,971         295     9.69
Top 5 Timed Events
~~~~~~~~~~~~~~~~~~                                                % Total
Event                                          Waits    Time (s) Ela Time
--------------------------------------- ------------ ----------- --------
latch free                                    10,969         666    51.28
buffer busy waits                             15,379         159    12.23
CPU time                                                     149    11.47
PL/SQL lock timer                                 51         105     8.05
db file sequential read                       25,163          96     7.36
Global Cache Service - Workload Characteristics       BAD   GOOD
Ave global cache get time (ms):                         11.8   2.2
Ave global cache convert time (ms):                     51.7  11.2
Ave build time for CR block (ms):                        0.7   0.0
Ave flush time for CR block (ms):                        0.2   0.2
Ave send time for CR block (ms):                         0.0   0.2
Ave time to process CR block request (ms):               0.9   0.4
Ave receive time for CR block (ms):                      1.6   0.4
Ave pin time for current block (ms):                     0.2   0.2
Ave flush time for current block (ms):                   0.0   0.0
Ave send time for current block (ms):                    0.1   0.1
Ave time to process current block request (ms):          0.3   0.3
Ave receive time for current block (ms):                33.4   7.5
Global cache hit ratio:                                  9.5   3.9
Ratio of current block defers:                           0.0   0.0
% of messages sent for buffer gets:                      6.7   2.5
% of remote buffer gets:                                 1.8   0.7
Ratio of I/O for coherence:                              1.2   1.3
Ratio of local vs remote work:                           4.3   4.4
Ratio of fusion vs physical writes:                      0.0   0.0
Global Enqueue Service Statistics        BAD   GOOD
Ave global lock get time (ms):                           0.2   0.0
Ave global lock convert time (ms):                       0.0   0.0
Ratio of global lock gets vs global lock releases:       1.2   1.1
GCS and GES Messaging statistics
Ave message sent queue time (ms):                       16.5   1.7
Ave message sent queue time on ksxp (ms):               29.4   2.5
Ave message received queue time (ms):                    1.9   0.3
Ave GCS message process time (ms):                       0.1   0.1
Ave GES message process time (ms):                       0.1   0.0
% of direct sent messages:                              49.7  63.4
% of indirect sent messages:                            50.3  36.6
% of flow controlled messages:                           0.0   0.0

For complete treatment of Oracle RAC tuning, see Mike Ault's book Oracle 10g Grid & Real Application Clusters



Oracle Training at Sea
oracle dba poster

Follow us on Twitter 
Oracle performance tuning software 
Oracle Linux poster


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.