Lecture
This lecture covers the concept of views in database systems, focusing on how they simplify the query writing process by allowing queries to be defined once and used in many instances. It explains how views are conceptual tables derived from existing tables, serving as a key component of data warehouses. The lecture delves into view definition, evaluate-on-demand views, view materialization, and the tradeoffs involved. It also discusses issues in view materialization, incremental view maintenance, computing data cubes from existing views, and cube building optimizations. The session concludes with a summary highlighting the importance of views in data warehouses and decision support systems.