An Oracle 10g Upgrade Case Study: Looking at System Performance Before and After the Upgrade

About The Client

Our client is a leading oracle consultancy serving more than 50 leading pubic and private sector clients. We were hired for providing Oracle 10g upgrade consultancy and to place backup/recovery rman procedures for 24 X 7 database.

Our Upgrade Strategy

The objectives were:

• Record the setup and configuration of the 8.7.4.1 to 10.2.0.3 Oracle Database Upgrade environment.
• Supplement the handover of the environment to Client DBA

We developed and tested our upgrade strategy by restoring a hot backup of the production database onto a test server similar to the production server and upgrading this database to Oracle 10g. Early on we decided to use the export/import method to perform the upgrade. This allowed us to switch all tablespaces to locally managed tablespaces, freshly install Oracle components, and compact all of our table and index segments. We might have been able to achieve most of these objectives with the Database Upgrade Assistant, but the prospect of starting with a "fresh" data dictionary appealed to us.

After we choreographed the upgrade procedure and ran through it successfully on the test server, the result was two test databases on the test server-an Oracle 8i database that was a carbon copy of production and an Oracle 10g database that contained the same data as production. This allowed us to run all sorts of tests to compare how the two versions of Oracle handled identical workloads and challenges.

Conclusion

Overall we have been pleased with Oracle 10g. It was easier than previous releases to install, the upgrade of our production database went smoothly, and we have not encountered compatibility issues. Although cleint application did not suddenly begin running faster after the upgrade to Oracle 10g, we expect to be able to get more out of our system once we start leveraging newer features (in a cautious manner with plenty of testing). Very few SQL statements in our application ran perceptibly slower after the upgrade, and they were easy to find and fix.