Systems Analysis and Design · Unit 6
Data Modeling and Database Design
Exam-focused notes for Data Modeling and Database Design (Systems Analysis and Design, BIT253): what the TU syllabus asks and how it has actually been tested, with 6 solved past questions from this unit.
What this unit covers
- Data modeling definition
- Entity-relationship diagram purpose and examples
- Conceptual data model
- Logical database design
- Physical database design
- Normalization definition
- First normal form
- Second normal form
- Index creation factors
- Goals of designing physical tables
- Object-oriented database benefits
- Object identity
Normalization definition
Define normalization. Explain first and second form of normalization. [1+4]
Normalization is the process of organizing the attributes and relations of a relational database to minimize data redundancy, eliminate undesirable insertion, deletion, and update anomalies, and ensure data integrity by decomposing larger tables into smalle...
Full solved answer →Index creation factors
What factors influence the decision to create an index on a field? What are the goals of designing physical tables? [3+2]
An index is a data structure that speeds up data retrieval. However, creating an index on every field is not always beneficial. The following factors influence the decision: - If a field is frequently used in WHERE clauses, JOIN conditions, or ORDER BY/GROU...
Full solved answer →Logical database design
Define conceptual data model. Explain logical database design in brief. [5]
--- A conceptual data model is a high-level, abstract representation of the data requirements of an organization, independent of any specific database management system (DBMS) or physical implementation details. It describes what data is stored, the relatio...
Full solved answer →Data modeling definition
What is data modeling? Draw an ER diagram to keep records of students, courses, and grades at your college. [5]
Data modeling is the process of creating a conceptual representation of data objects, the associations between different data objects, and the rules governing those objects. It defines how data is connected to each other and how they are processed and store...
Full solved answer →Object-oriented database benefits
What are the benefits of object-oriented database? What is object identity? [5]
--- Object-oriented databases combine the features of object-oriented programming with database capabilities. The key benefits are: - OODB can store complex, real-world objects (e.g., images, audio, documents) that are difficult to represent in relational t...
Full solved answer →Entity-relationship diagram purpose and examples
Why do we need ER diagram during information system development? Explain with example. [5]
An Entity-Relationship (ER) Diagram is a graphical/visual representation of the logical structure of a database. It shows entities, their attributes, and the relationships among them. It was introduced by Peter Chen in 1976. --- ER diagrams provide a clear ...
Full solved answer →Make Unit 6 stick
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