1-Based on your understanding of specialization and generalization constraints,

1-Based on your understanding of specialization and generalization constraints,

1-Based on your understanding of specialization and generalization constraints, use your own words to define and discuss the two primary constraints: Disjointness Constraint and Completeness Constraint
2-Show the schema mapping of the following Payment EER schema diagram, using Option 8A: Multiple relations-Superclass and subclasses.
3- SQL constraints are used to specify rules for the data in a table. From what has been studied, what is the benefit of using constraints in DB. Also, explain three common SQL constraints.
4-Using the relational algebra operations, write the following queries on the COMPANY relational database schema shown in the figure below.
(a)Retrieve the address of employees in department 2 who work less than 5 hours per week on the ‘ProductX’ project.
(b)Retrieve the names and salary of employees who work on every project.