This lecture covers heuristic-based optimization techniques used in database systems, focusing on the example of the INGRES system. The instructor explains how static rules are defined to transform logical operators into a physical plan, emphasizing the importance of performing selections early and before joins. The lecture delves into the INGRES optimizer, demonstrating the process of retrieving data from a database using SQL queries. The advantages and disadvantages of heuristic-based optimization are discussed, highlighting its effectiveness for simple queries but limitations in handling complex joins and interdependencies.