Jeff Smith, via Twitter, asked a very good question about my previous post regarding baseline plans when upgrading from 10g to 11g, (or for previous versions, which I can also go into the steps in how to ensure more consistent performance during upgrades from earlier versions as well to 11g…) “…this assumes that new 11g plans wouldn’t be ‘better’..right? Are people gun-shy b/c 9-10 upgrade issues?” Why would we want to go back to 10g performance when we have just upgraded to a beautiful new version of 11g? Many responded in the Twitter conversation in regards to insurance and this…

When involved in an 11g upgrade of a 10g database, one of the important goals for a DBA is to maintain the same performance in the newly upgraded environment as the previous one. One of the best ways to accomplish this is through baseline collection of the execution plans that then can be imported and loaded directly into the SQL Plan Baseline once the database is upgraded. The disclaimer needs to be added, you must have a license for the tuning pack, so always check your DBA_FEATURE_USAGE_STATISTICS view and ensure you are in compliance. The steps to complete this are…