Questions from Database Systems

Q: Under what circumstances would the query / Include tuples with

Under what circumstances would the query Include tuples with null values for the title attribute?

Q: Show how to define a view to credits (year, numb

Show how to define a view to credits (year, numb credits), giving the total number of credits taken in each year.

Q: For the view of Exercise 4.18, explain why the

For the view of Exercise 4.18, explain why the database system would not allow a tuple to be inserted into the database through this view.

Q: Show how to express the coalesce function using the case construct.

Show how to express the coalesce function using the case construct.

Q: Write a Java program that allows university administrators to print the teaching

Write a Java program that allows university administrators to print the teaching record of an instructor. a. Start by having the user input the login ID and password; then open the proper connection....

Q: Modify the recursive query in Figure 5.16 to define a

Modify the recursive query in Figure 5.16 to define a relation Prefer depth (course id, prefer id, depth) Where the attribute depth indicates how many levels of intermediate prerequisites there are bet...

Q: Consider the advisor relation shown in the schema diagram in Figure 2

Consider the advisor relation shown in the schema diagram in Figure 2.9, with s id as the primary key of advisor. Suppose a student can have more than one advisor. Then, would s I d still be a primary...

Q: Assume that two students are trying to register for a course in

Assume that two students are trying to register for a course in which there is only one open seat. What component of a database system prevents both students from being given that last seat?

Q: Given relation s (a, b, c), write an

Given relation s (a, b, c), write an SQL statement to generate a histogram show- ing the sum of c values versus a, dividing a tin to 20 equal-sized partitions (i.e., where each partition contains 5 pe...

Q: Consider the nice relation of Exercise 5.9. For each

Consider the nice relation of Exercise 5.9. For each month of each year, show the total monthly dollar volume and the average monthly dollar volume for that month and the two prior months. (Hint: Firs...