Relational Query Optimization

This lecture covers the process of relational query optimization, including logical and physical query plans, query transformations, equivalences in relational algebra, cost estimation, statistics and catalogs, size estimation, reduction factors, and the System R strategy. The instructor explains the phases of query optimization, the importance of query blocks, and the selection-project-join optimization core. Various examples are provided to illustrate the concepts, such as result size estimation for selections and natural joins. The lecture concludes with an overview of the query optimization phases and the improved strategy used in System R.