15. Use the Internet to find definitions for the terms equi-join, natural join, and cross join. Write a short report that identifies how these terms relate to the terms join, inner join, and Cartesian product. Be sure to reference your online sources properly. Multiple-Table Queries 16. Use the Internet to find information on cost-based query optimizers. Write a short report that explains how cost-based query optimization works, and what type(s) of queries benefit the most from cost-based query optimization. Be sure to reference your online sources properly