CS 551 Final Exam

You are to answer each question briefly and to the point. Your answer should demonstrate your clear understanding of the concept. 

1. Transactions require the four properties knows as ACID properties. For each, describe the mechanism by which the DBMS can enforce it.


2. Does a checkpoint in transaction processing, allow save all the work done by all transactions up to the checkpoint. Explain briefly and clearly.



3. Explain the meaning of a serializable schedule for a set of transactions.



4. How does the Two-Phase Locking Protocol restrict lock acqusitions?



5. In typical 3VL, how does the DBMS treat the unk value with respect to database integrity constraints? Explain the rationale for this.



6. What is the purpose of the Outer Join?




7. What is the purpose of a guard condition in a DDBMS?



8. What is the basic idea behind the semijoin operation? 



9. What are three  factors which a centralized query optimizer considers when deciding on a query execution strategy?


10. What is the goal of synthesis design? What are the inputs and outputs of this process?