Introduction to normalization. Introduction to normalization

Save this PDF as:

Size: px
Start display at page:

Download "Introduction to normalization. Introduction to normalization"

Transcription

1 Introduction to normalization Lecture 4 Instructor Anna Sidorova Agenda Presentation Review of relational models, in class exersise Introduction to normalization In-class exercises Discussion of HW2 1

2 Next class Review for the midterm HW 2 is due March 7 midterm exam Based on Hoffer, Prescott and Topi Modern Database Management, (c) Prentice Hall 2009 HW 2 Chapter 4, Problem 6 develop a relational schema Convert ERD for Ch. 2, Problem 20 (a part of your HW1) into a relational schema (must be based on the correct solution) Chapter 4, Problems 7 and 8 (we will discuss the relevant material next class) Handout normalization exercises Based on Hoffer, Prescott and Topi Modern Database Management, (c) Prentice Hall

3 Review of relational data models Figure 2-7 Three-schema architecture Different people have different views of the database these these are the external schema The internal schema is the underlying design and implementation Based on Hoffer, Prescott and Topi Modern Database Management, (c) Prentice Hall

4 Relation Definition: A relation is a named, two-dimensional table of data Table consists of rows (records) and columns (attribute or field) Requirements for a table to qualify as a relation: It must have a unique name Every attribute value must be atomic (not multivalued, not composite) Every row must be unique (can t have two rows with exactly the same values for all their fields) Attributes (columns) in tables must have unique names The order of the columns must be irrelevant The order of the rows must be irrelevant NOTE: all relations are in 1 st Normal form Translating ERD into relational schema Map each entity into a relation Map each weak entity into a relation (include the identifier of the strong entity as a part of the primary key) Map each multivalued attribute into a relation (include the identifier of the entity as a part of the primary key) Map many-to-many relationships and associative entities into a relation Represent one-to-one and one-to-many relationships using foreign keys. Based on Hoffer, Prescott and Topi Modern Database Management, (c) Prentice Hall

5 Normalization Learning Objectives Define Normalization Define 1 st, 2 nd and 3 rd Normal Forms Discuss normalization process 5

6 Normalization: Definitions Normalization is a method used to validate and improve a logical design so that it satisfies certain constraints that avoid unnecessary duplication of data The process of decomposing relations with anomalies to produce smaller, well-structured relations 9.11 Well-Structured Relations A relation that contains minimal data redundancy and allows users to insert, delete, ete, and update rows without causing data inconsistencies Goal is to avoid anomalies Insertion Anomaly adding adding new rows forces user to create duplicate data Deletion Anomaly deleting rows may cause a loss of data that would be needed for other future rows Modification Anomaly changing data in a row forces changes to other rows because of duplication 12 6

7 Example Figure 5-2b Question Is this a relation? Question What s the primary key? Answer Yes: Unique rows and no multivalued attributes Answer Composite: Emp_ID, Course_Title 13 Anomalies in this Table Insertion can t enter a new employee without having the employee take a class Deletion if if we remove employee 140, we lose information about the existence of a Tax Acc class Modification giving a salary increase to employee 100 forces us to update multiple records Why do these anomalies exist? Because there are two themes (entity types) in this one relation. This results in data duplication and an unnecessary dependency between the entities 14 7

8 Normalization Process The goal is to bring each relation into the Third Normal Form. The process bringing a relation into the 3 rd Normal Form Goes through stages. 1 st Normal Form 2 nd Normal Form 3 rd Normal Form Functional Dependencies Functional Dependency A particular relationship between two attributes. For a given relation, attribute B is functionally dependent on attribute A if, for every valid value of A, that value of A uniquely determines the value of B Instances (or sample data) in a relation do not prove the existence of a functional dependency Knowledge of problem domain is most reliable method for identifying functional dependency

9 Functional Dependencies: Notations in Problems A B Attribute B is functionally dependent on attribute A (A determines B) A, B C Attributes A and B together determine attribute C A B, C Both attributes, B and C are determined by (functionally dependent on) attribute A Functional Dependencies We can draw functional dependencies between attributes of a relation as follows: STUDENT Stud_ID F_Name L_Name 111 Mary Jones 122 Sara Smith 9

10 Important Definitions Multivalued Attributes (repeating groups) non-key attributes or groups of non-key attributes the values of which are not uniquely identified d by (directly or indirectly) (not functionally dependent on) the value of the Primary Key (or its part). STUDENT Stud_ID Name Course_ID Units 101 Lennon MSI Lennon MSI Jonson MSI Important Definitions A relation is unnormalized (not in the 1 st Normal Form) if it has multivalued l attributes or repeating groups. STUDENT Repeating Group Stud_ID Name Course_ID Units 101 Lennon MSI Lennon MSI Jonson MSI

11 Important Definitions A relation is in the 1 st Normal Form if it has no multivalued attributes or repeating groups. STUDENT Stud_ID Name Course_ID Units 101 Lennon MSI Lennon MSI Jonson MSI Important Definitions Partial Dependency when an non-key attribute is determined d by a part, but not the whole, of a COMPOSITE primary key. CUSTOMER Partial Dependency Cust_ID Name Order_ID 101 AT&T AT&T Cisco

12 Important Definitions A relation is NOT in the 2 nd Normal Form if it has partial dependencies. d CUSTOMER Partial Dependency Cust_ID Name Order_ID 101 AT&T AT&T Cisco 1250 Important Definitions A relation is in the 2 nd Normal Form if it is in the 1 st Normal Form AND has no partial dependencies. d EMPLOYEE Emp_ID F_Name L_Name Dept_ID Dept_Name 111 Mary Jones 1 Acct 122 Sara Smith 2 Mktg 12

13 Important Definitions Transitive Dependency when a non-key attribute determines another non-key attribute. EMPLOYEE Transitive Dependency Emp_ID F_Name L_Name Dept_ID Dept_Name 111 Mary Jones 1 Acct 122 Sara Smith 2 Mktg Important Definitions A relation is NOT in the 3 rd Normal Form if it has transitive dependencies. EMPLOYEE Transitive Dependency Emp_ID F_Name L_Name Dept_ID Dept_Name 111 Mary Jones 1 Acct 122 Sara Smith 2 Mktg 13

14 Important Definitions A relation is in the 3 rd Normal Form if it is in the 2 nd Normal Form and has no transitive dependencies. EMPLOYEE Emp_ID F_Name L_Name Dept_ID 111 Mary Jones Sara Smith 2 Normal Forms: Review Unnormalized There are multivalued attributes or repeating groups 1 NF No multivalued attributes or repeating groups. 2 NF 1 NF plus no partial dependencies 3 NF 2 NF plus no transitive dependencies

15 Example 1: Determine NF ISBN Title ISBN Publisher Publisher Address All attributes are directly or indirectly determined by the primary key; therefore, the relation is at least in 1 NF BOOK ISBN Title Publisher Address Example 1: Determine NF ISBN Title ISBN Publisher Publisher Address BOOK The relation is at least in 1NF. There is no COMPOSITE primary key, therefore there can t be partial dependencies. Therefore, the relation is at least in 2NF ISBN Title Publisher Address 15

16 Example 1: Determine NF ISBN Title ISBN Publisher Publisher Address BOOK Publisher is a non-key attribute, and it determines Address, another non-key attribute. Therefore, there is a transitive dependency, which means that the relation is NOT in 3 NF. ISBN Title Publisher Address Example 1: Determine NF ISBN Title ISBN Publisher Publisher Address We know that the relation is at least in 2NF, and it is not in 3 NF. Therefore, we conclude that the relation is in 2NF. BOOK ISBN Title Publisher Address 16

17 Example 1: Determine NF ISBN Title ISBN Publisher Publisher Address In your solution you will write the following justification: 1) No M/V attributes, therefore at least 1NF 2) No partial dependencies, therefore at least 2NF 3) There is a transitive dependency (Publisher Address), therefore, not 3NF Conclusion: The relation is in 2NF BOOK ISBN Title Publisher Address Example 2: Determine NF Product_ID Description ORDER All attributes are directly or indirectly determined by the primary key; therefore, the relation is at least in 1 NF Order_No Product_ID Description 17

18 Example 2: Determine NF Product_ID Description ORDER The relation is at least in 1NF. There is a COMPOSITE Primary Key (PK) (Order_No, Product_ID), therefore there can be partial dependencies. Product_ID, which is a part of PK, determines Description; hence, there is a partial dependency. Therefore, the relation is not 2NF. No sense to check for transitive dependencies! Order_No Product_ID Description Example 2: Determine NF Product_ID Description ORDER We know that the relation is at least in 1NF, and it is not in 2 NF. Therefore, we conclude that the relation is in 1 NF. Order_No Product_ID Description 18

19 Example 2: Determine NF Product_ID Description ORDER In your solution you will write the following justification: 1) No M/V attributes, therefore at least 1NF 2) There is a partial dependency (Product_ID Description), therefore not in 2NF Conclusion: The relation is in 1NF Order_No Product_ID Description Example 3: Determine NF Part_ID Description Part_ ID Price Part_ID, Comp_ID No Comp_ID and No are not determined by the primary key; therefore, the relation is NOT in 1 NF. No sense in looking at partial or transitive dependencies. PART Part_ID Descr Price Comp_ID No 19

20 Example 3: Determine NF Product_ID Description Product_ID Price Part_ID, Comp_ID No In your solution you will write the following justification: 1) There are M/V attributes; therefore, not 1NF Conclusion: The relation is unnormalized. PART Part_ID Descr Price Comp_ID No Bringing a Relation to 1NF STUDENT Stud_ID Name Course_ID Units 101 Lennon MSI Lennon MSI Jonson MSI

21 Bringing a Relation to 1NF Option 1: Make a determinant of the repeating group (or a multivalued attribute) a part of the primary key. STUDENT Composite Primary Key Stud_ID Name Course_ID Units 101 Lennon MSI Lennon MSI Jonson MSI Bringing a Relation to 1NF Option 2: Remove the entire repeating group from the relation. Create another relation which would contain all the attributes of the repeating group, plus the primary key from the first relation. In this new relation, the primary key from the original ii relation and the determinant of the repeating group will comprise a primary key. STUDENT Stud_ID Name Course_ID Units 101 Lennon MSI Lennon MSI Jonson MSI

22 Bringing a Relation to 1NF STUDENT Stud_ID Name 101 Lennon 101 Lennon 125 Jonson STUDENT_COURSE Stud_ID Course Units 101 MSI MSI MSI Bringing a Relation to 2NF Composite Primary Key STUDENT Stud_ID Name Course_ID Units 101 Lennon MSI Lennon MSI Jonson MSI

23 Bringing a Relation to 2NF Goal: Remove Partial Dependencies Composite Primary Key Partial Dependencies STUDENT Stud_ID Name Course_ID Units 101 Lennon MSI Lennon MSI Jonson MSI Bringing a Relation to 2NF Remove attributes that are dependent from the part but not the whole of the primary key from the original relation. For each partial dependency, create a new relation, with the corresponding part of the primary key from the original as the primary key. STUDENT Stud_ID Name Course_ID Units 101 Lennon MSI Lennon MSI Jonson MSI

24 Bringing a Relation to 2NF CUSTOMER Stud_ID Name Course_ID Units 101 Lennon MSI Lennon MSI Jonson MSI STUDENT_COURSE Stud_ID Course_ID 101 MSI MSI MSI 331 STUDENT Stud_ID Name 101 Lennon 101 Lennon 125 Jonson COURSE Course_ID Units MSI MSI MSI Bringing a Relation to 3NF Goal: Get rid of transitive dependencies. EMPLOYEE Transitive Dependency Emp_ID F_Name L_Name Dept_ID Dept_Name 111 Mary Jones 1 Acct 122 Sara Smith 2 Mktg 24

25 Bringing a Relation to 3NF Remove the attributes, which are dependent on a non-key attributes from the original relation. For each transitive dependency, d create a new relation with the non-key attributes which is a determinant in the transitive dependency as a primary key, and the dependent non-key attribute as a dependent. EMPLOYEE Emp_ID F_Name L_Name Dept_ID Dept_Name 111 Mary Jones 1 Acct 122 Sara Smith 2 Mktg Bringing a Relation to 3NF EMPLOYEE Emp_ID F_Name L_Name Dept_ID Dept_Name 111 Mary Jones 1 Acct 122 Sara Smith 2 Mktg EMPLOYEE Emp_ID F_Name L_Name Dept_ID 111 Mary Jones Sara Smith 2 DEPARTMENT Dept_ID Dept_Name 1 Acct 2 Mktg 25

26 Other Normal Forms (from Appendix B) Boyce-Codd NF All determinants are candidate d keys there is no determinant that is not a unique identifier Usually, if a relation is in #NF it is in the BCNF, except when a part of the primary key is determined by a non-key attribute. 4 th NF and 5 th NF used primarily for theoretical purposes Merging Relations View Integration Combining entities from multiple ER models into common relations Issues to watch out for when merging entities from different ER models: Synonyms two or more attributes with different names but same meaning Homonyms attributes with same name but different meanings Transitive dependencies even if relations are in 3NF prior to merging, they may not be after merging Supertype/subtype relationships may be hidden prior to merging 26

27 Enterprise Keys advice from some experts Primary keys that are unique in the whole database, not just within a single relation Corresponds with the concept of an object ID in object-oriented systems 27

28 In class exercise See handout Based on Hoffer, Prescott and Topi Modern Database Management, (c) Prentice Hall

Chapter 5: Logical Database Design and the Relational Model Part 2: Normalization. Introduction to Normalization. Normal Forms.

Chapter 5: Logical Database Design and the Relational Model Part 2: Normalization. Introduction to Normalization. Normal Forms. Chapter 5: Logical Database Design and the Relational Model Part 2: Normalization Modern Database Management 6 th Edition Jeffrey A. Hoffer, Mary B. Prescott, Fred R. McFadden Robert C. Nickerson ISYS

More information

Fundamentals of Database System

Fundamentals of Database System Fundamentals of Database System Chapter 4 Normalization Fundamentals of Database Systems (Chapter 4) Page 1 Introduction To Normalization In general, the goal of a relational database design is to generate

More information

Normalization. CIS 3730 Designing and Managing Data. J.G. Zheng Fall 2010

Normalization. CIS 3730 Designing and Managing Data. J.G. Zheng Fall 2010 Normalization CIS 3730 Designing and Managing Data J.G. Zheng Fall 2010 1 Overview What is normalization? What are the normal forms? How to normalize relations? 2 Two Basic Ways To Design Tables Bottom-up:

More information

Database Design. Marta Jakubowska-Sobczak IT/ADC based on slides prepared by Paula Figueiredo, IT/DB

Database Design. Marta Jakubowska-Sobczak IT/ADC based on slides prepared by Paula Figueiredo, IT/DB Marta Jakubowska-Sobczak IT/ADC based on slides prepared by Paula Figueiredo, IT/DB Outline Database concepts Conceptual Design Logical Design Communicating with the RDBMS 2 Some concepts Database: an

More information

A. TRUE-FALSE: GROUP 2 PRACTICE EXAMPLES FOR THE REVIEW QUIZ:

A. TRUE-FALSE: GROUP 2 PRACTICE EXAMPLES FOR THE REVIEW QUIZ: GROUP 2 PRACTICE EXAMPLES FOR THE REVIEW QUIZ: Review Quiz will contain very similar question as below. Some questions may even be repeated. The order of the questions are random and are not in order of

More information

Normalization in OODB Design

Normalization in OODB Design Normalization in OODB Design Byung S. Lee Graduate Programs in Software University of St. Thomas St. Paul, Minnesota bslee@stthomas.edu Abstract When we design an object-oriented database schema, we need

More information

DATABASE NORMALIZATION

DATABASE NORMALIZATION DATABASE NORMALIZATION Normalization: process of efficiently organizing data in the DB. RELATIONS (attributes grouped together) Accurate representation of data, relationships and constraints. Goal: - Eliminate

More information

Bridge from Entity Relationship modeling to creating SQL databases, tables, & relations

Bridge from Entity Relationship modeling to creating SQL databases, tables, & relations 1 Topics for this week: 1. Good Design 2. Functional Dependencies 3. Normalization Readings for this week: 1. E&N, Ch. 10.1-10.6; 12.2 2. Quickstart, Ch. 3 3. Complete the tutorial at http://sqlcourse2.com/

More information

DATABASE SYSTEMS. Chapter 7 Normalisation

DATABASE SYSTEMS. Chapter 7 Normalisation DATABASE SYSTEMS DESIGN IMPLEMENTATION AND MANAGEMENT INTERNATIONAL EDITION ROB CORONEL CROCKETT Chapter 7 Normalisation 1 (Rob, Coronel & Crockett 978184480731) In this chapter, you will learn: What normalization

More information

If it's in the 2nd NF and there are no non-key fields that depend on attributes in the table other than the Primary Key.

If it's in the 2nd NF and there are no non-key fields that depend on attributes in the table other than the Primary Key. Normalization First Normal Form (1st NF) The table cells must be of single value. Eliminate repeating groups in individual tables. Create a separate table for each set of related data. Identify each set

More information

Normalization. Functional Dependence. Normalization. Normalization. GIS Applications. Spring 2011

Normalization. Functional Dependence. Normalization. Normalization. GIS Applications. Spring 2011 Normalization Normalization Normalization is a foundation for relational database design Systematic approach to efficiently organize data in a database GIS Applications Spring 2011 Objectives Minimize

More information

COSC344 Database Theory and Applications. Lecture 9 Normalisation. COSC344 Lecture 9 1

COSC344 Database Theory and Applications. Lecture 9 Normalisation. COSC344 Lecture 9 1 COSC344 Database Theory and Applications Lecture 9 Normalisation COSC344 Lecture 9 1 Overview Last Lecture Functional Dependencies This Lecture Normalisation Introduction 1NF 2NF 3NF BCNF Source: Section

More information

Normalisation to 3NF. Database Systems Lecture 11 Natasha Alechina

Normalisation to 3NF. Database Systems Lecture 11 Natasha Alechina Normalisation to 3NF Database Systems Lecture 11 Natasha Alechina In This Lecture Normalisation to 3NF Data redundancy Functional dependencies Normal forms First, Second, and Third Normal Forms For more

More information

Normalization in Database Design

Normalization in Database Design in Database Design Marek Rychly mrychly@strathmore.edu Strathmore University, @ilabafrica & Brno University of Technology, Faculty of Information Technology Advanced Databases and Enterprise Systems 14

More information

Chapter 6. Database Tables & Normalization. The Need for Normalization. Database Tables & Normalization

Chapter 6. Database Tables & Normalization. The Need for Normalization. Database Tables & Normalization Chapter 6 Database Tables & Normalization Objectives: to learn What normalization is and what role it plays in the database design process About the normal forms 1NF, 2NF, 3NF, BCNF, and 4NF How normal

More information

Data Model ing Essentials

Data Model ing Essentials Data Model ing Essentials Third Edition Graeme C. Simsion and Graham C. Witt MORGAN KAUFMANN PUBLISHERS AN IMPRINT OF ELSEVIER AMSTERDAM BOSTON LONDON NEW YORK OXFORD PARIS SAN DIEGO SAN FRANCISCO SINGAPORE

More information

Normalization. Normalization. First goal: to eliminate redundant data. for example, don t storing the same data in more than one table

Normalization. Normalization. First goal: to eliminate redundant data. for example, don t storing the same data in more than one table Normalization Normalization Purpose Redundancy and Data Anomalies 1FN: First Normal Form 2FN: Second Normal Form 3FN: Thrird Normal Form Examples 1 Normalization Normalization is the process of efficiently

More information

Teaching Database Modeling and Design: Areas of Confusion and Helpful Hints

Teaching Database Modeling and Design: Areas of Confusion and Helpful Hints Journal of Information Technology Education Volume 6, 2007 Teaching Database Modeling and Design: Areas of Confusion and Helpful Hints George C. Philip, Ph. D. College of Business, The University of Wisconsin

More information

Databases -Normalization III. (N Spadaccini 2010 and W Liu 2012) Databases - Normalization III 1 / 31

Databases -Normalization III. (N Spadaccini 2010 and W Liu 2012) Databases - Normalization III 1 / 31 Databases -Normalization III (N Spadaccini 2010 and W Liu 2012) Databases - Normalization III 1 / 31 This lecture This lecture describes 3rd normal form. (N Spadaccini 2010 and W Liu 2012) Databases -

More information

Database Design and Normalization

Database Design and Normalization Database Design and Normalization CPS352: Database Systems Simon Miner Gordon College Last Revised: 9/27/12 Agenda Check-in Functional Dependencies (continued) Design Project E-R Diagram Presentations

More information

MCQs~Databases~Relational Model and Normalization http://en.wikipedia.org/wiki/database_normalization

MCQs~Databases~Relational Model and Normalization http://en.wikipedia.org/wiki/database_normalization http://en.wikipedia.org/wiki/database_normalization Database normalization is the process of organizing the fields and tables of a relational database to minimize redundancy. Normalization usually involves

More information

Normalization of Database

Normalization of Database Normalization of Database UNIT-4 Database Normalisation is a technique of organizing the data in the database. Normalization is a systematic approach of decomposing tables to eliminate data redundancy

More information

DATABASE DESIGN: NORMALIZATION NOTE & EXERCISES (Up to 3NF)

DATABASE DESIGN: NORMALIZATION NOTE & EXERCISES (Up to 3NF) DATABASE DESIGN: NORMALIZATION NOTE & EXERCISES (Up to 3NF) Tables that contain redundant data can suffer from update anomalies, which can introduce inconsistencies into a database. The rules associated

More information

Normalisation 6 TABLE OF CONTENTS LEARNING OUTCOMES

Normalisation 6 TABLE OF CONTENTS LEARNING OUTCOMES Topic Normalisation 6 LEARNING OUTCOMES When you have completed this Topic you should be able to: 1. Discuss importance of the normalisation in the database design. 2. Discuss the problems related to data

More information

Functional Dependency and Normalization for Relational Databases

Functional Dependency and Normalization for Relational Databases Functional Dependency and Normalization for Relational Databases Introduction: Relational database design ultimately produces a set of relations. The implicit goals of the design activity are: information

More information

Chapter 15 Basics of Functional Dependencies and Normalization for Relational Databases

Chapter 15 Basics of Functional Dependencies and Normalization for Relational Databases Chapter 15 Basics of Functional Dependencies and Normalization for Relational Databases Copyright 2011 Pearson Education, Inc. Publishing as Pearson Addison-Wesley Chapter 15 Outline Informal Design Guidelines

More information

Chapter 10. Functional Dependencies and Normalization for Relational Databases

Chapter 10. Functional Dependencies and Normalization for Relational Databases Chapter 10 Functional Dependencies and Normalization for Relational Databases Chapter Outline 1 Informal Design Guidelines for Relational Databases 1.1Semantics of the Relation Attributes 1.2 Redundant

More information

RELATIONAL DATABASE DESIGN

RELATIONAL DATABASE DESIGN RELATIONAL DATABASE DESIGN g Good database design - Avoiding anomalies g Functional Dependencies g Normalization & Decomposition Using Functional Dependencies g 1NF - Atomic Domains and First Normal Form

More information

Database Design and the Reality of Normalisation

Database Design and the Reality of Normalisation Proceedings of the NACCQ 2000 Wellington NZ www.naccq.ac.nz Database Design and the Reality of Normalisation Dave Kennedy ABSTRACT Institute of Technology Christchurch Polytechnic Te Whare Runanga O Otautahi

More information

Chapter 9: Normalization

Chapter 9: Normalization Chapter 9: Normalization Part 1: A Simple Example Part 2: Another Example & The Formal Stuff A Problem: Keeping Track of Invoices (cont d) Suppose we have some invoices that we may or may not want to refer

More information

DATABASE INTRODUCTION

DATABASE INTRODUCTION Introduction The history of database system research is one of exceptional productivity and startling economic impact. We have learnt that from the days of file-based systems there are better ways to handle

More information

Part 6. Normalization

Part 6. Normalization Part 6 Normalization Normal Form Overview Universe of All Data Relations (normalized / unnormalized 1st Normal Form 2nd Normal Form 3rd Normal Form Boyce-Codd Normal Form (BCNF) 4th Normal Form 5th Normal

More information

Database design 1 The Database Design Process: Before you build the tables and other objects that will make up your system, it is important to take time to design it. A good design is the keystone to creating

More information

Normal forms and normalization

Normal forms and normalization Normal forms and normalization An example of normalization using normal forms We assume we have an enterprise that buys products from different supplying companies, and we would like to keep track of our

More information

Introduction to Computing. Lectured by: Dr. Pham Tran Vu t.v.pham@cse.hcmut.edu.vn

Introduction to Computing. Lectured by: Dr. Pham Tran Vu t.v.pham@cse.hcmut.edu.vn Introduction to Computing Lectured by: Dr. Pham Tran Vu t.v.pham@cse.hcmut.edu.vn Databases The Hierarchy of Data Keys and Attributes The Traditional Approach To Data Management Database A collection of

More information

CS 377 Database Systems. Database Design Theory and Normalization. Li Xiong Department of Mathematics and Computer Science Emory University

CS 377 Database Systems. Database Design Theory and Normalization. Li Xiong Department of Mathematics and Computer Science Emory University CS 377 Database Systems Database Design Theory and Normalization Li Xiong Department of Mathematics and Computer Science Emory University 1 Relational database design So far Conceptual database design

More information

Lecture 2 Normalization

Lecture 2 Normalization MIT 533 ระบบฐานข อม ล 2 Lecture 2 Normalization Walailuk University Lecture 2: Normalization 1 Objectives The purpose of normalization The identification of various types of update anomalies The concept

More information

Chapter 10. Functional Dependencies and Normalization for Relational Databases. Copyright 2007 Ramez Elmasri and Shamkant B.

Chapter 10. Functional Dependencies and Normalization for Relational Databases. Copyright 2007 Ramez Elmasri and Shamkant B. Chapter 10 Functional Dependencies and Normalization for Relational Databases Copyright 2007 Ramez Elmasri and Shamkant B. Navathe Chapter Outline 1 Informal Design Guidelines for Relational Databases

More information

Relational Database Basics Review

Relational Database Basics Review Relational Database Basics Review IT 4153 Advanced Database J.G. Zheng Spring 2012 Overview Database approach Database system Relational model Database development 2 File Processing Approaches Based on

More information

DATABASE MANAGEMENT SYSTEMS. Question Bank:

DATABASE MANAGEMENT SYSTEMS. Question Bank: DATABASE MANAGEMENT SYSTEMS Question Bank: UNIT 1 1. Define Database? 2. What is a DBMS? 3. What is the need for database systems? 4. Define tupule? 5. What are the responsibilities of DBA? 6. Define schema?

More information

IT2305 Database Systems I (Compulsory)

IT2305 Database Systems I (Compulsory) Database Systems I (Compulsory) INTRODUCTION This is one of the 4 modules designed for Semester 2 of Bachelor of Information Technology Degree program. CREDITS: 04 LEARNING OUTCOMES On completion of this

More information

CIS 631 Database Management Systems Sample Final Exam

CIS 631 Database Management Systems Sample Final Exam CIS 631 Database Management Systems Sample Final Exam 1. (25 points) Match the items from the left column with those in the right and place the letters in the empty slots. k 1. Single-level index files

More information

Developing Entity Relationship Diagrams (ERDs)

Developing Entity Relationship Diagrams (ERDs) Developing Entity Relationship Diagrams (ERDs) Introduction This document seeks to give expanded explanation and examples of how to produce entity relationship diagrams. It is based on material adapted

More information

CS143 Notes: Normalization Theory

CS143 Notes: Normalization Theory CS143 Notes: Normalization Theory Book Chapters (4th) Chapters 7.1-6, 7.8, 7.10 (5th) Chapters 7.1-6, 7.8 (6th) Chapters 8.1-6, 8.8 INTRODUCTION Main question How do we design good tables for a relational

More information

Files. Files. Files. Files. Files. File Organisation. What s it all about? What s in a file?

Files. Files. Files. Files. Files. File Organisation. What s it all about? What s in a file? Files What s it all about? Information being stored about anything important to the business/individual keeping the files. The simple concepts used in the operation of manual files are often a good guide

More information

Fundamentals of Database Design

Fundamentals of Database Design Fundamentals of Database Design Zornitsa Zaharieva CERN Data Management Section - Controls Group Accelerators and Beams Department /AB-CO-DM/ 23-FEB-2005 Contents : Introduction to Databases : Main Database

More information

CPS352 Database Systems: Design Project

CPS352 Database Systems: Design Project CPS352 Database Systems: Design Project Purpose: Due: To give you experience with designing and implementing a database to model a real domain Various milestones due as shown in the syllabus Requirements

More information

SAMPLE FINAL EXAMINATION SPRING SESSION 2015

SAMPLE FINAL EXAMINATION SPRING SESSION 2015 SAMPLE FINAL EXAMINATION SPRING SESSION 2015 School of Computing, Engineering and Mathematics Student family name: Student given name/s: Student ID number: Course: Unit Name (In Full): Database Design

More information

Unit 3.1. Normalisation 1 - V2.0 1. Normalisation 1. Dr Gordon Russell, Copyright @ Napier University

Unit 3.1. Normalisation 1 - V2.0 1. Normalisation 1. Dr Gordon Russell, Copyright @ Napier University Normalisation 1 Unit 3.1 Normalisation 1 - V2.0 1 Normalisation Overview discuss entity integrity and referential integrity describe functional dependency normalise a relation to first formal form (1NF)

More information

C HAPTER 4 INTRODUCTION. Relational Databases FILE VS. DATABASES FILE VS. DATABASES

C HAPTER 4 INTRODUCTION. Relational Databases FILE VS. DATABASES FILE VS. DATABASES INRODUCION C HAPER 4 Relational Databases Questions to be addressed in this chapter: How are s different than file-based legacy systems? Why are s important and what is their advantage? What is the difference

More information

IT2304: Database Systems 1 (DBS 1)

IT2304: Database Systems 1 (DBS 1) : Database Systems 1 (DBS 1) (Compulsory) 1. OUTLINE OF SYLLABUS Topic Minimum number of hours Introduction to DBMS 07 Relational Data Model 03 Data manipulation using Relational Algebra 06 Data manipulation

More information

DBMS. Normalization. Module Title?

DBMS. Normalization. Module Title? Normalization Database Normalization Database normalization is the process of removing redundant data from your tables in to improve storage efficiency, data integrity (accuracy and consistency), and scalability

More information

Conceptual Design: Entity Relationship Models. Objectives. Overview

Conceptual Design: Entity Relationship Models. Objectives. Overview Conceptual Design: Entity Relationship Models Craig Van Slyke, University of Central Florida cvanslyke@bus.ucf.edu John Day, Ohio University Objectives Define terms related to entity relationship modeling,

More information

Database Design Basics

Database Design Basics Database Design Basics Table of Contents SOME DATABASE TERMS TO KNOW... 1 WHAT IS GOOD DATABASE DESIGN?... 2 THE DESIGN PROCESS... 2 DETERMINING THE PURPOSE OF YOUR DATABASE... 3 FINDING AND ORGANIZING

More information

The process of database development. Logical model: relational DBMS. Relation

The process of database development. Logical model: relational DBMS. Relation The process of database development Reality (Universe of Discourse) Relational Databases and SQL Basic Concepts The 3rd normal form Structured Query Language (SQL) Conceptual model (e.g. Entity-Relationship

More information

Normalization. Reduces the liklihood of anomolies

Normalization. Reduces the liklihood of anomolies Normalization Normalization Tables are important, but properly designing them is even more important so the DBMS can do its job Normalization the process for evaluating and correcting table structures

More information

Chapter 10 Functional Dependencies and Normalization for Relational Databases

Chapter 10 Functional Dependencies and Normalization for Relational Databases Chapter 10 Functional Dependencies and Normalization for Relational Databases Copyright 2004 Pearson Education, Inc. Chapter Outline 1 Informal Design Guidelines for Relational Databases 1.1Semantics of

More information

Tutorial on Relational Database Design

Tutorial on Relational Database Design Tutorial on Relational Database Design Introduction Relational database was proposed by Edgar Codd (of IBM Research) around 1969. It has since become the dominant database model for commercial applications

More information

7.1 The Information system

7.1 The Information system Chapter 7. Database Planning, Design and Administration Last few decades have seen proliferation of software applications, many requiring constant maintenance involving: correcting faults, implementing

More information

Normalization. Normalization. Normalization. Data Redundancy

Normalization. Normalization. Normalization. Data Redundancy Normalization Normalization o Main objective in developing a logical data model for relational database systems is to create an accurate representation of the data, its relationships, and constraints.

More information

14 Databases. Source: Foundations of Computer Science Cengage Learning. Objectives After studying this chapter, the student should be able to:

14 Databases. Source: Foundations of Computer Science Cengage Learning. Objectives After studying this chapter, the student should be able to: 14 Databases 14.1 Source: Foundations of Computer Science Cengage Learning Objectives After studying this chapter, the student should be able to: Define a database and a database management system (DBMS)

More information

CSCI-GA.2433-001 Database Systems Lecture 7: Schema Refinement and Normalization

CSCI-GA.2433-001 Database Systems Lecture 7: Schema Refinement and Normalization CSCI-GA.2433-001 Database Systems Lecture 7: Schema Refinement and Normalization Mohamed Zahran (aka Z) mzahran@cs.nyu.edu http://www.mzahran.com View 1 View 2 View 3 Conceptual Schema At that point we

More information

Module 5: Normalization of database tables

Module 5: Normalization of database tables Module 5: Normalization of database tables Normalization is a process for evaluating and correcting table structures to minimize data redundancies, thereby reducing the likelihood of data anomalies. The

More information

Data Modeling: Part 1. Entity Relationship (ER) Model

Data Modeling: Part 1. Entity Relationship (ER) Model Data Modeling: Part 1 Entity Relationship (ER) Model MBA 8473 1 Cognitive Objectives (Module 2) 32. Explain the three-step process of data-driven information system (IS) development 33. Examine the purpose

More information

MODULE 8 LOGICAL DATABASE DESIGN. Contents. 2. LEARNING UNIT 1 Entity-relationship(E-R) modelling of data elements of an application.

MODULE 8 LOGICAL DATABASE DESIGN. Contents. 2. LEARNING UNIT 1 Entity-relationship(E-R) modelling of data elements of an application. MODULE 8 LOGICAL DATABASE DESIGN Contents 1. MOTIVATION AND LEARNING GOALS 2. LEARNING UNIT 1 Entity-relationship(E-R) modelling of data elements of an application. 3. LEARNING UNIT 2 Organization of data

More information

Normalization. CIS 331: Introduction to Database Systems

Normalization. CIS 331: Introduction to Database Systems Normalization CIS 331: Introduction to Database Systems Normalization: Reminder Why do we need to normalize? To avoid redundancy (less storage space needed, and data is consistent) To avoid update/delete

More information

Denormalisation (But not hacking it)

Denormalisation (But not hacking it) Denormalisation (But not hacking it) Denormalisation: Why, What, and How? Rodgers Oracle Performance Tuning Corrigan/Gurry Ch. 5, p69 Stephen Mc Kearney, 2001. 1 Overview Purpose of normalisation Methods

More information

Normalisation 1. Chapter 4.1 V4.0. Copyright @ Napier University

Normalisation 1. Chapter 4.1 V4.0. Copyright @ Napier University Normalisation 1 Chapter 4.1 V4.0 Copyright @ Napier University Normalisation Overview discuss entity integrity and referential integrity describe functional dependency normalise a relation to first formal

More information

Carnegie Mellon Univ. Dept. of Computer Science 15-415 - Database Applications. Overview - detailed. Goal. Faloutsos CMU SCS 15-415

Carnegie Mellon Univ. Dept. of Computer Science 15-415 - Database Applications. Overview - detailed. Goal. Faloutsos CMU SCS 15-415 Faloutsos 15-415 Carnegie Mellon Univ. Dept. of Computer Science 15-415 - Database Applications Lecture #17: Schema Refinement & Normalization - Normal Forms (R&G, ch. 19) Overview - detailed DB design

More information

Foundations of Information Management

Foundations of Information Management Foundations of Information Management - WS 2012/13 - Juniorprofessor Alexander Markowetz Bonn Aachen International Center for Information Technology (B-IT) Data & Databases Data: Simple information Database:

More information

Announcements. SQL is hot! Facebook. Goal. Database Design Process. IT420: Database Management and Organization. Normalization (Chapter 3)

Announcements. SQL is hot! Facebook. Goal. Database Design Process. IT420: Database Management and Organization. Normalization (Chapter 3) Announcements IT0: Database Management and Organization Normalization (Chapter 3) Department coin design contest deadline - February -week exam Monday, February 1 Lab SQL SQL Server: ALTER TABLE tname

More information

C# Cname Ccity.. P1# Date1 Qnt1 P2# Date2 P9# Date9 1 Codd London.. 1 21.01 20 2 23.01 2 Martin Paris.. 1 26.10 25 3 Deen London.. 2 29.

C# Cname Ccity.. P1# Date1 Qnt1 P2# Date2 P9# Date9 1 Codd London.. 1 21.01 20 2 23.01 2 Martin Paris.. 1 26.10 25 3 Deen London.. 2 29. 4. Normalisation 4.1 Introduction Suppose we are now given the task of designing and creating a database. How do we produce a good design? What relations should we have in the database? What attributes

More information

Theory of Relational Database Design and Normalization

Theory of Relational Database Design and Normalization Theory of Relational Database Design and Normalization (Based on Chapter 14 and some part of Chapter 15 in Fundamentals of Database Systems by Elmasri and Navathe, Ed. 3) 1 Informal Design Guidelines for

More information

Database Normalization. Mohua Sarkar, Ph.D Software Engineer California Pacific Medical Center 415-600-7003 sarkarm@sutterhealth.

Database Normalization. Mohua Sarkar, Ph.D Software Engineer California Pacific Medical Center 415-600-7003 sarkarm@sutterhealth. Database Normalization Mohua Sarkar, Ph.D Software Engineer California Pacific Medical Center 415-600-7003 sarkarm@sutterhealth.org Definition A database is an organized collection of data whose content

More information

2. Conceptual Modeling using the Entity-Relationship Model

2. Conceptual Modeling using the Entity-Relationship Model ECS-165A WQ 11 15 Contents 2. Conceptual Modeling using the Entity-Relationship Model Basic concepts: entities and entity types, attributes and keys, relationships and relationship types Entity-Relationship

More information

The 3 Normal Forms: Copyright Fred Coulson 2007 (last revised February 1, 2009)

The 3 Normal Forms: Copyright Fred Coulson 2007 (last revised February 1, 2009) The 3 Normal Forms: A Tutorial by Fred Coulson Copyright Fred Coulson 2007 (last revised February 1, 2009) This tutorial may be freely copied and distributed, providing appropriate attribution to the author

More information

Exercise 1: Relational Model

Exercise 1: Relational Model Exercise 1: Relational Model 1. Consider the relational database of next relational schema with 3 relations. What are the best possible primary keys in each relation? employ(person_name, street, city)

More information

3. Relational Model and Relational Algebra

3. Relational Model and Relational Algebra ECS-165A WQ 11 36 3. Relational Model and Relational Algebra Contents Fundamental Concepts of the Relational Model Integrity Constraints Translation ER schema Relational Database Schema Relational Algebra

More information

Database Design Methodologies

Database Design Methodologies Critical Success Factors in Database Design Database Design Methodologies o Work interactively with the users as much as possible. o Follow a structured methodology throughout the data modeling process.

More information

Functional Dependencies and Finding a Minimal Cover

Functional Dependencies and Finding a Minimal Cover Functional Dependencies and Finding a Minimal Cover Robert Soulé 1 Normalization An anomaly occurs in a database when you can update, insert, or delete data, and get undesired side-effects. These side

More information

Relational Database Concepts

Relational Database Concepts Relational Database Concepts IBM Information Management Cloud Computing Center of Competence IBM Canada Labs 1 2011 IBM Corporation Agenda Overview Information and Data Models The relational model Entity-Relationship

More information

Data Modeling Basics

Data Modeling Basics Information Technology Standard Commonwealth of Pennsylvania Governor's Office of Administration/Office for Information Technology STD Number: STD-INF003B STD Title: Data Modeling Basics Issued by: Deputy

More information

Databases Model the Real World. The Entity- Relationship Model. Conceptual Design. Steps in Database Design. ER Model Basics. ER Model Basics (Contd.

Databases Model the Real World. The Entity- Relationship Model. Conceptual Design. Steps in Database Design. ER Model Basics. ER Model Basics (Contd. The Entity- Relationship Model R &G - Chapter 2 A relationship, I think, is like a shark, you know? It has to constantly move forward or it dies. And I think what we got on our hands is a dead shark. Woody

More information

Functional Dependencies

Functional Dependencies BCNF and 3NF Functional Dependencies Functional dependencies: modeling constraints on attributes stud-id name address course-id session-id classroom instructor Functional dependencies should be obtained

More information

Chapter 5: FUNCTIONAL DEPENDENCIES AND NORMALIZATION FOR RELATIONAL DATABASES

Chapter 5: FUNCTIONAL DEPENDENCIES AND NORMALIZATION FOR RELATIONAL DATABASES 1 Chapter 5: FUNCTIONAL DEPENDENCIES AND NORMALIZATION FOR RELATIONAL DATABASES INFORMAL DESIGN GUIDELINES FOR RELATION SCHEMAS We discuss four informal measures of quality for relation schema design in

More information

An Example: Video Rental System

An Example: Video Rental System An Example: Video Rental System Video Rental Database Customers Rentals Videos E-R Analysis ERD Example CUSTOMER PRODUCER E-R Analysis Attributes Attribute - property or characteristic of an entity type

More information

DATABASE DESIGN: Normalization Exercises & Answers

DATABASE DESIGN: Normalization Exercises & Answers DATABASE DESIGN: Normalization Exercises & Answers (a) The table shown in Figure 1 is susceptible to update anomalies. Provide examples of insertion, deletion, and modification anomalies. Answers: This

More information

Topic 5.1: Database Tables and Normalization

Topic 5.1: Database Tables and Normalization Topic 5.1: Database Tables and Normalization What is Normalization? Normalization is a process for evaluating and correcting table structures to minimize data redundancies, thereby helping to eliminate

More information

Databases What the Specification Says

Databases What the Specification Says Databases What the Specification Says Describe flat files and relational databases, explaining the differences between them; Design a simple relational database to the third normal form (3NF), using entityrelationship

More information

Database IST400/600. Jian Qin. A collection of data? A computer system? Everything you collected for your group project?

Database IST400/600. Jian Qin. A collection of data? A computer system? Everything you collected for your group project? Relational Databases IST400/600 Jian Qin Database A collection of data? Everything you collected for your group project? A computer system? File? Spreadsheet? Information system? Date s criteria: Integration

More information

- Eliminating redundant data - Ensuring data dependencies makes sense. ie:- data is stored logically

- Eliminating redundant data - Ensuring data dependencies makes sense. ie:- data is stored logically Normalization of databases Database normalization is a technique of organizing the data in the database. Normalization is a systematic approach of decomposing tables to eliminate data redundancy and undesirable

More information

BCA. Database Management System

BCA. Database Management System BCA IV Sem Database Management System Multiple choice questions 1. A Database Management System (DBMS) is A. Collection of interrelated data B. Collection of programs to access data C. Collection of data

More information

Understanding the Database Design Process

Understanding the Database Design Process 67232976x_ch15.qxd 4/1/8 4:3 PM Page 1 15 Understanding the Database Design Process In this chapter, you ll learn the thought processes behind designing a relational database. After this theory-focused

More information

Optimum Database Design: Using Normal Forms and Ensuring Data Integrity. by Patrick Crever, Relational Database Programmer, Synergex

Optimum Database Design: Using Normal Forms and Ensuring Data Integrity. by Patrick Crever, Relational Database Programmer, Synergex Optimum Database Design: Using Normal Forms and Ensuring Data Integrity by Patrick Crever, Relational Database Programmer, Synergex Printed: April 2007 The information contained in this document is subject

More information

Lecture Notes INFORMATION RESOURCES

Lecture Notes INFORMATION RESOURCES Vilnius Gediminas Technical University Jelena Mamčenko Lecture Notes on INFORMATION RESOURCES Part I Introduction to Dta Modeling and MSAccess Code FMITB02004 Course title Information Resourses Course

More information

City University of Hong Kong. Information on a Course offered by Department of Computer Science with effect from Semester A in 2014 / 2015

City University of Hong Kong. Information on a Course offered by Department of Computer Science with effect from Semester A in 2014 / 2015 City University of Hong Kong Information on a Course offered by Department of Computer Science with effect from Semester A in 2014 / 2015 Part I Course Title: Database Systems Course Code: CS3402 Course

More information

Database Design and the E-R Model

Database Design and the E-R Model C H A P T E R 7 Database Design and the E-R Model Practice Exercises 7.1 Answer: The E-R diagram is shown in Figure 7.1. Payments are modeled as weak entities since they are related to a specific policy.

More information

Design of Relational Database Schemas

Design of Relational Database Schemas Design of Relational Database Schemas T. M. Murali October 27, November 1, 2010 Plan Till Thanksgiving What are the typical problems or anomalies in relational designs? Introduce the idea of decomposing

More information

Database Design for the Uninitiated CDS Brownbag Series CDS

Database Design for the Uninitiated CDS Brownbag Series CDS Database Design for the Uninitiated Paul Litwin FHCRC Collaborative Data Services 1 CDS Brownbag Series This is the ninth in a series of seminars Materials for the series can be downloaded from www.deeptraining.com/fhcrc

More information

Information Systems Analysis and Design CSC340. 2004 John Mylopoulos Database Design -- 2. Information Systems Analysis and Design CSC340

Information Systems Analysis and Design CSC340. 2004 John Mylopoulos Database Design -- 2. Information Systems Analysis and Design CSC340 XX. Database Design Databases Databases and DBMS Data Models, Hierarchical, Network, Relational Database Design Restructuring an ER schema Performance analysis Analysis of Redundancies, Removing generalizations

More information