Data Modelling 2023 Exam Questions with Correct Answers

Data Modelling 2023 Exam Questions with Correct Answers 1) What is data modelling? - CORRECT ANSWER i) Data modelling is the process of creating a model for the data to store in a database. ii) It is a conceptual representation of data objects, the association between different data objects, and the rules. 2) Explain various types of data models - CORRECT ANSWER There are mainly three different types of data models: Conceptual: i) Conceptual data model defines what should the system contain. ii) This model is typically created by business stakeholders and data architects. iii) The purpose is to organize, scope, and define business concepts and rules. Logical: i) Defines how the system should be implemented regardless of the DBMS. ii) This model is typically created by data architects and business analysts. iii) The purpose is to develop a technical map of rules and data structures. Physical: i) This data model describes how the system will be implemented using a specific DBMS system. ii) This model is typically created by DBA and developers. iii) The purpose is the actual implementation of the database. 3) Explain the fact and fact table - CORRECT ANSWER i) The fact represents quantitative data. ii) For example, the net amount which is due. iii) A fact table contains numerical data as well as foreign keys from dimensional tables. 4) List out various design schema in data modelling - CORRECT ANSWER There are two different types of data modelling schemas: 1) Star Schema, and 2) Snowflake Schema 5) When should you consider denormalization? - CORRECT ANSWER Denormalization is used when there is a lot of involvement of the table while retrieving data. It is used to construct a data warehouse.