You start work Monday morning hopeful to mark a few things off your to-do list. Before you can even finish your first cup of caffeinated beverage, you’re getting pinged, and your inbox is filling with alerts. Hoping into your database monitoring tools, it’s clear that the production database is on fire. After a half hour of troubleshooting, you find that at least one query has changed execution plan, for the worse. How did this happen?
There is a good chance that Oracle’s adaptive SQL optimization features caused the query plan to change. In this session we will walk through how these features work, why they exist, and how you might be hindering them. Instead of fighting the Optimizer, we will discuss what is needed to make it successful. Covering Adaptive Query Optimization, Statistics Feedback, Adaptive Dynamic Sampling, and Adaptive Cursor Sharing.