DATABASE SYSTEM CONCEPTS (LOOSELEAF)
7th Edition
ISBN: 9781260515046
Author: SILBERSCHATZ
Publisher: MCG
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Chapter 3, Problem 32E
Explanation of Solution
Query:
The query for the given scenario:
SELECT distinct teaches.ID, Name FROM takes, teaches, instructor WHERE teaches.course_id = takes.course_id AND instructor.Id = teaches.Id and Grade is not NULL AND teaches.ID not in (SELECT distinct teaches.Id FROM takes, teaches WHERE teaches.course_id = takes.course_id and Grade="A");
Explanation:
- The subquery(inner select query) finds teacher Id's who have given Grade "A" in any course that they teach...
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Suppose that the two Rank methods below are added to the Skip List class on Blackboard.
public int Rank (T item)
Returns the rank of the given item.
public T Rank(int i)
Returns the item with the given rank i.
Requirements
1. Describe in a separate Design Document what additional data is needed and how that data is used to
support an expected time complexity of O(log n) for each of the Rank methods. Show as well that the
methods Insert and Remove can efficiently maintain this data as items are inserted and removed. (7
marks)
2. Re-implement the methods Insert and Remove of the Skip List class to maintain the augmented data in
expected O(log n) time. Using the Contains method, ensure that added items are distinct. (6 marks)
3. Implement the two Rank methods. (8 marks)
4. Test your new methods thoroughly. Include your test cases and results in a Test Document. (4 marks)
Suppose that the two Rank methods below are added to the Skip List class on Blackboard.
public int Rank (T item)
Returns the rank of the given item.
public T Rank(int i)
Returns the item with the given rank i.
Requirements
1. Describe in a separate Design Document what additional data is needed and how that data is used to
support an expected time complexity of O(log n) for each of the Rank methods. Show as well that the
methods Insert and Remove can efficiently maintain this data as items are inserted and removed. (7
marks)
2. Re-implement the methods Insert and Remove of the Skip List class to maintain the augmented data in
expected O(log n) time. Using the Contains method, ensure that added items are distinct. (6 marks)
3. Implement the two Rank methods. (8 marks)
4. Test your new methods thoroughly. Include your test cases and results in a Test Document. (4 marks)
automata theory
Chapter 3 Solutions
DATABASE SYSTEM CONCEPTS (LOOSELEAF)
Ch. 3 - Prob. 1PECh. 3 - Prob. 2PECh. 3 - Prob. 3PECh. 3 -
Suppose that we have a relation marks(ID, score)...Ch. 3 - Suppose that we have a relation marks(ID, score)...Ch. 3 -
The SQL like operator is case sensitive (in most...Ch. 3 - Prob. 7PECh. 3 - Prob. 8PECh. 3 - Prob. 9PECh. 3 - Prob. 10PE
Ch. 3 - Prob. 11ECh. 3 - Prob. 12ECh. 3 - Prob. 13ECh. 3 -
Consider the insurance database of Figure 3.17,...Ch. 3 - Prob. 15ECh. 3 - Prob. 16ECh. 3 - Prob. 17ECh. 3 - Prob. 18ECh. 3 -
List two reasons why null values might be...Ch. 3 - Prob. 20ECh. 3 - Prob. 21ECh. 3 - Prob. 22ECh. 3 - Prob. 23ECh. 3 - Prob. 24ECh. 3 - Prob. 25ECh. 3 - Prob. 26ECh. 3 - Using the university schema, write an SQL query to...Ch. 3 - Prob. 28ECh. 3 - Prob. 29ECh. 3 - Prob. 30ECh. 3 - Prob. 31ECh. 3 - Prob. 32ECh. 3 - Prob. 33ECh. 3 - Prob. 34ECh. 3 - Prob. 35E
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