In this session, we'll delve deep into the world of query optimisers, contrasting their performance across three of the world's leading RDBMS: PostgreSQL, MySQL, and SQL Server. These database systems, boasting a rich history and widespread adoption by enterprises both on-premises and in the cloud, each bring unique strengths and intricacies to the table. If you're evaluating which database to adopt for your upcoming projects, or simply curious about the inner workings and unexpected outcomes of query optimisation, this is a must-attend. Expect a blend of in-depth insights, engaging discussions, and surprising results!