Oracle Database 11g: Database Replay, Part 2 - Page 4
May 30, 2008
Phase 4: Regression Analysis
Oracle 11g gives me several tools for comparing the captured vs. replayed workloads. As shown in Figures 2.5.1 and 2.5.2 below, the most succinct comparison is the one that Database Replay provides immediately after a successful replay operation has completed:
Click for larger image
Click for larger image
As these summaries illustrate, its obvious that the changes Ive made to the databases objects have had an overall positive effect because the time it took to execute the captured workload is significantly longer than the time it took to replay the identical workload, and that immediately indicates that the system modifications have positively increased database throughput. Its just as important to note, however, that there were no deleterious effects introduced. This is easiest to see in the second half of the regression analysis screen because there is absolutely no divergence between the generated data, and there were no unexpected errors generated.
Finally, Database Replay offers several reports in HTML format that analyze the results of the completed database replay operation:
In the final article in this series, Ill expand on the scenario that played out in this article by tackling one of the thornier concerns most Oracle DBAs have for systems that are about to migrate to Oracle 11g: How will my current database perform in a brand-new environment? And to make it even more relevant and interesting, Ill target a two-node Oracle 11g Real Application Cluster (RAC) clustered database as the testing environment.
References and Additional Reading
While Im hopeful that Ive given you a thorough grounding in the technical aspects of the features Ive discussed in this article, Im also sure that there may be better documentation available since its been published. I therefore strongly suggest that you take a close look at the corresponding Oracle documentation on these features to obtain crystal-clear understanding before attempting to implement them in a production environment. Please note that Ive drawn upon the following Oracle Database 11gR1 documentation for the deeper technical details of this article:
B28274-01 Oracle Database 11gR1 Performance Tuning Guide
B28279-02 Oracle Database 11gR1 New Features Guide
B28419-02 Oracle Database 11gR1 PL/SQL Packages and Types Reference