Understanding QTA fundamentals

While guiding us through the recommended process, QTA doesn’t follow it exactly. The very last step, step 5, will not have the same outcome we saw in the previous section; instead of providing options to revert to a last known good plan, QTA helps to find a new state that is not the pre-CE upgrade or post-CE upgrade plan but a new plan that will hopefully outperform both of the previous plans.

The following diagram summarizes the recommended steps to minimize risk with CE upgrades using QTA, which replaces the very last step of the process described in the previous Understanding where QTA and CE Feedback are needed section:

Figure 12.4: The recommended steps to minimize risk with CE upgrades using QTA

How does QTA find a better query plan for regressed queries? Starting with the same data that’s available in Query Store’s Regressed Queries report, QTA will look for query patterns that may be affected...