Chapter 10 Exercise 12

12. If it does not already exist, create a sales query that uses data from the Customer, Sales, SaleItems, Employee, and City tables to produce a report of all sales sorted by state. Use a query analyzer to evaluate the query and identify methods to improve its performance.

This question depends on the tools and DBMS available. Access results are limited to identifying indexes. Oracle and SQL Server provide more detailed analysis and optimization. See the respective Workbook for the steps to run the analyzer in your chosen DBMS. The most common result is that the system will recommend indexes on all of the join columns (but they probably exist already).