This lecture covers two approaches for code generation in database systems: transpilation and JIT compilation. It explains the concept of operator templates and the blurred boundaries in operator abstractions. The lecture also delves into push-based models for query compilation, LLVM code generation, and the benefits of query compilation in major DBMS. Additionally, it discusses adapting data formats, the processing model of a DBMS, and the various operational systems and data sources involved in query processing.