Call for Oracle support & training (800) 766-1884
Free Oracle Tips

Corporate Oracle Training
Custom Oracle Training
Oracle New Features Training
Advanced Oracle DBA Classes
Oracle Tuning Courses
Oracle Tips & Tricks
Oracle Training Links
Oracle Training Links
Oracle Training Links

We are top for USA Oracle Training Clients


Free Oracle Tips


Free Oracle App Server Tips


Oracle support

Oracle training

Oracle tuning


Remote Oracle

Custom Oracle Training


  Oracle Tips by Burleson

RAC Design Considerations

Proper Sequence Usage

  • A problem with sequences is indicated in a v$system_event as an extended average wait time for row cache locks in the range of a few hundred milliseconds. The proportion of time waiting for row cache locks to the total time waiting for non-idle events will be relatively high.

  • In the v$rowcache view, for the dc_sequences parameter, the ratio of dlm_conflicts to dlm_requests will be high. If this ratio exceeds 10 to 15%, and the row cache lock wait time is a significant portion of the total wait time, then it is likely that the service time deterioration is due to insufficiently cached sequences. For example:

SQL> col parameter format a15
SQL> select parameter, dlm_conflicts
, dlm_requests, dlm_conflicts/dlm_requests ratio
   2 from v$rowcache
   3 where dlm_requests>0;

--------------- -------------- --------------   -----------
dc_sequences                 0              2             0

For more information, see the book Oracle 11g Grid and Real Application Clusters 30% off if you buy it directly from Rampant TechPress . 

Written by top Oracle experts, this RAC book has a complete online code depot with ready to use RAC scripts.

Remote DBA Services

Burleson Consulting can offer world-class remote Oracle database support at super-affordable prices.

Our remote Oracle DBA service provides 100% of the remote Oracle database administration needs for your company, and includes 24x7 access to our staff of 100% OCP Certified Oracle DBAs. 

We require a 12 month service commitment and include the following services:

  • Initial configuration review and problem identification
  • Installation of Oracle statistics collection mechanisms and quarterly database growth summaries
  • Hourly monitoring of your Oracle database for pending problems
  • Periodic performance analysis & identification of tuning activities
  • Twenty Four hour Oracle emergency support
  • Reporting and resolving all serious Oracle alert log messages
  • Free use of the BC TablePack, ServerPack and AuditPack services
  • Quick response emergency support for production database outages
  • Four hours of free remote DBA support every month. You can use these free hours for any DBA activity, including database analysis, system design, production migrations or personal mentoring.

For more information, please visit


Oracle performance tuning book



Oracle performance tuning software

Oracle performance tuning software
Oracle performance Tuning 10g reference poster
Oracle training in Linux commands
Oracle training Excel


email BC:

Copyright © 1996 -  2014 by Burleson Inc. All rights reserved.

Oracle® is the registered trademark of Oracle Corporation.