Explain the concept of physical data independence

Assignment Help Database Management System
Reference no: EM1379750

1. Explain the concept of physical data independence and its importance in database systems

2. Explain what problems are caused by the design of the following table.

The Customer table attached in complete requirement doc file

3. List four significant differences between a file-processing system and a DBMS.

4. Describe the differences in meaning between the terms relation and relation schema.

5. List two reasons why null values might be introduced into the database.

6. Write the following queries in SQL, using the university schema. (Appendix A, page 1271)

a. Find the titles of courses in the Biology department that have 4 credits.

b. Find the lowest salary of instructor in Comp. Sci. department.

c. Find the enrollment of each section that was offered in Fall 2011.

d. Find the minimum enrollment, across all sections, in Fall 2011.

e. Find the sections that had the minimum enrollment in Fall 2011.

7. Write the following queries in SQL, using the university schema. (Appendix A, page 1271)

a. Find the names of all students who have taken at least one Comp. Sci. course; make sure there

are no duplicate names in the result.

b. Find the IDs and names of all students who have not taken any course offering before Spring

2009.

c. For each department, find the maximum salary of instructors in that department. You may

assume that every department has at least one instructor.

d. Find the highest, across all departments, of the per-department maximum salary computed by

the preceding query (part 7.c).

e. Find the course titles of all prerequisite courses of "CS-315".

8. Write the following queries in SQL, using the university schema. (Appendix A, page 1271)

a. Create a new course "CS-001", titled "Weekly Seminar", with 1 credit.

b. Create a section of this course in Fall 2011, with sec_idof 1.

c. Delete the course CS-001. What will happen if you run this delete statement without first

deleting offerings (sections) of this course?

9. Show that (proof), in SQL, <>all is identical to not in.

10. Show how to define a view total_credits(year, num_credits), giving the total number of

credits taken by students in each year. a


Download:- requirement.rar

Reference no: EM1379750

Questions Cloud

Printf statement to debug an application : There are various ways to debug a program, perhaps most elementary is using a printf() statement to show important pieces of data regarding the program execution point,
How does framing a message affect communication process : How does framing a message affect communication process. How could your message be reframed so that it is processed also received with improved results.
Briefly explain what two parameters on x-axis also y-axis : briefly explain what two parameters on X-axis also Y-axis mean also provide an example for each explanation.
Evaluate purpose also usefulness of these surveys : We see surveys on all kinds of store receipts allowing consumers to give feedback in exchange for being entered into a drawing for a prize. Evaluate purpose also usefulness of these surveys. Consider all stakeholders in your answer.
Explain the concept of physical data independence : Explain the concept of physical data independence and its importance in database systems,  List four significant differences between a file-processing system and a DBMS.
Crontab script for various jobs : Construct a crontab to perform tasks given below at the frequencies specified. Run a backup script named local-backup from the /usr/local/adm directory every weekday at 11:30pm.
Discuss two strategic reasons for companies to engage : Briefly discuss two strategic reasons for companies to engage in practice of countertrade. Assuming that your company has decided to get involved in countertrade.
What are strengths of such an organization : Transnational Solution" suggests that technical also marketing functions be integrated within each subsidiary of any organization. What are strengths of such an organization. What are weaknesses or pitfalls.
Are following objective functions for an lp model equivalent : Are following objective functions for an LP model equivalent. That is, if they are both used, one at a time, to solve a problem with exactly same constraints, will optimal values of X1 also X2 be same in both cases.

Reviews

Write a Review

Database Management System Questions & Answers

  Knowledge and data warehousing

Design a dimensional model for analysing Purchases for Adventure Works Cycles and implement it as cubes using SQL Server Analysis Services. The AdventureWorks OLTP sample database is the data source for you BI analysis.

  Design a database schema

Design a Database schema

  Entity-relationship diagram

Create an entity-relationship diagram and design accompanying table layout using sound relational modeling practices and concepts.

  Implement a database of courses and students for a school

Implement a database of courses and students for a school.

  Prepare the e-r diagram for the movie database

Energy in the home, personal energy use and home energy efficiency and Efficient use of ‘waste' heat and renewable heat sources

  Design relation schemas for the entire database

Design relation schemas for the entire database.

  Prepare the relational schema for database

Prepare the relational schema for database

  Data modeling and normalization

Data Modeling and Normalization

  Use cases perform a requirements analysis for the case study

Use Cases Perform a requirements analysis for the Case Study

  Knowledge and data warehousing

Knowledge and Data Warehousing

  Stack and queue data structure

Identify and explain the differences between a stack and a queue data structure

  Practice on topic of normalization

Practice on topic of Normalization

Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd