Database Management System · Unit 7 · 7 hrs
Relational Database Design
Exam-focused notes for Relational Database Design (Database Management System, CSC265): what the TU syllabus asks and how it has actually been tested, with 7 solved past questions from this unit.
What this unit covers
- Relational Database Design Using ER-to-Relational Mapping
- Informal Design Guidelines for Relational Schemas
- Functional Dependencies
- Normal Forms Based on Primary Keys
- General Definitions of Second and Third Normal Forms
- Boyce-Codd Normal Form
- Multivalued Dependency and Fourth Normal Form
- Properties of Relational Decomposition
Normal Forms Based on Primary Keys
Define normalization. Why normalization is important in database design? Explain 1NF, 2NF and 3NF with suitable example.[10]
Normalization is the process of organizing the attributes and tables of a relational database to minimize data redundancy and dependency. It involves decomposing a large, poorly structured table into smaller, well-structured tables while preserving data int...
Full solved answer →What is normal form? Explain their types. Explain about loss-less join decomposition.[10]
The normal form of a relation refers to the highest normal form condition that it meets, and hence indicates the degree to which it has been normalized. Normal forms are used to eliminate redundancy, insertion anomalies, deletion anomalies, and update anoma...
Full solved answer →General Definitions of Second and Third Normal Forms
What is normalization? Why normalization is required? Explain 1NF, 2NF, and 3NF with example.[10]
--- Normalization is the process of organizing the attributes and tables of a relational database to reduce data redundancy and improve data integrity. It involves decomposing a large, poorly structured table into smaller, well-structured tables while prese...
Full solved answer →Functional Dependencies
Define functional dependencies. Explain 2nd normal form with example. [5]
--- A functional dependency is a constraint between two sets of attributes in a relation. For a relation R, a functional dependency X → Y means that the value of attribute set X uniquely determines the value of attribute set Y. - X is called the determinant...
Full solved answer →Define Functional dependencies. Explain trivial and non trivial dependencies? [5]
A functional dependency is a constraint between two sets of attributes in a relation. For a relation R, a functional dependency is denoted as: X → Y This means attribute (or set of attributes) X functionally determines attribute (or set of attributes) Y. In...
Full solved answer →Boyce-Codd Normal Form
Define Boyce-Codd normal form with example. How it is different that 3rd Normal form. [5]
Boyce-Codd Normal Form (BCNF) is a stronger version of the Third Normal Form (3NF). A relation R is in BCNF if and only if for every non-trivial functional dependency X → Y, X must be a superkey (i.e., X must be a candidate key or a superset of a candidate ...
Full solved answer →Informal Design Guidelines for Relational Schemas
What are informal design guidelines for relational schemas? why do we need functional dependencies? Explain 2NF, 3NF with suitable example.[10]
--- Informal guidelines are used as measures to determine the quality of relation schema design. The four main guidelines are: --- Design a relation schema so that it is easy to explain its meaning. Do not combine attributes from multiple entity types into ...
Full solved answer →Make Unit 7 stick
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