Oracle 18c SQL Performance Tuning

Learn how different join types affect SQL performance, and how to choose the right one. We’ll cover nested loops, merge joins, hash joins and more, giving you the practical know-how to optimise multi-table queries. You'll also explore less common operations like star joins, anti joins and semi joins. Understanding how joins work under the hood helps you write queries that perform well even as data volumes grow and business logic becomes more complex. 

Oracle gives you tools to gently steer the Optimiser; hints are one of the most effective. We’ll show you how to use them wisely, from influencing join order and access paths to overriding default behaviour when you know better. You’ll see when hints make sense, when they don’t, and how to test the effect they’re having. It’s a great way to take more control of performance without rewriting entire queries. 

SQL and PL/SQL often work side by side, and that’s where hidden performance costs can creep in. We’ll look at how these two languages interact, how to spot inefficiencies and where tuning PL/SQL can improve overall SQL speed. Topics include bind variables, cursor management and shared pool issues. You’ll get a better sense of how backend logic influences SQL behaviour and how small changes can unlock smoother performance.