COMP 266 Lecture Notes - Lecture 3: Referential Integrity, Database Design, Third Normal Form

Why do relational databases use primary keys and foreign keys?

1. To create a database
2. To create a logical relationship
3. To create a physical relationship
4. All of these

8. We use transistors to construct gates, the diagram below represents the gate. Source Emitter Ground a. NOT b. AND c. OR d. XOR

12. The diagram below represents possible process states, suppose that one process is sharing the CPU with two other processes and all data for all processes are in memory and no special event is expected; then, the process would be running in sequence loop Waiting Input/output or event completion Input/output or event wait Interrupt Ready Running Dispatch Admitted Exit New Terminated a. Ready, Running b. Running, Waiting Ready C. Running, Terminated d. dispatch, exit