The Query Processor is one of the most sophisticated components of an RDBMS, and SQL Server is no exception. Many enhancements have been introduced to make query processing more efficient. In this session, we will cover the topic by walking through the various features, starting with the new “Cardinality Estimator” model introduced in SQL Server 2014, and leading up to everything that falls under the umbrella term “Intelligent Query Processing,” including “Adaptive Query Processing” features introduced in SQL Server 2017 and the new capabilities added in SQL Server 2019. We will also cover the features that help manage potential performance regression issues, supported by practical demonstrations.