It is only important to identify the primary key for one table in joining the two tables

Which of the following statements about layered operating systems is true?

a) Layered operating systems group components that perform similar functions into layers. b) Layered operating systems are easier to modify than monolithic operating systems. c) User processes’ requests may need to interact with multiple layers, resulting in slower performance than in a monolithic system. d) all of the above.

Give an example in the Student Registration System where the database satis?es the integrity constraints IC0–IC3 but its state does not re?ect the state of the real world.

What will be an ideal response?What will be an ideal response?