- What inputs do you need for BUILDING a data model? …
- What are various differences between CONCEPTUAL data model and LOGICAL data model? …
- What are the activities carried out in a Physical Data Modeling?
Feeling jittery before your Data Modeler interview? Check out these most commonly asked data modelling interview questions with the best possible responses. Last Updated: 15 Sep 2022
Be it among the 296K data analysts jobs or 153K data engineer jobs in the US, data modeling seems to be an essential skill for every IT candidate to possess, but it can be difficult to master. So, if you are preparing for a big data job interview for roles like data modelers, business analysts, etc., then this blog is the best resource! We have compiled the top 50 data modelling interview questions and answers from beginner to advanced levels. These data modelling interview questions will benefit data modelers, data engineers, business analysts, and anyone willing to pursue a career in big data or data science.
Erwin Data Modeling Interview Questions – Part 1
What is an artificial key, and when should it be used?
This content-specific question determines if you can focus on helping clients organize data to better access information quickly. Your answer allows you to display your expertise in data modeling versus .storage modeling.
It shows your confidence in creating models that are stable and can hold accessible information for clients.
Example: “As chief engineer at ABC company, one of my tasks was to help entry-level engineers with the artificial key. They had to create a system of storing data that would not change, even if the value on other fields changed. A natural key is one that happens organically as part of the database and changes equally when others do change. A derived key, also known as an artificial key or surrogate key, violates the principle of stability.
Essentially, it has no real value to the system other than what has been created. We used the surrogate key to store information with no semantic meaning for our client. It allowed them to have fields for employees’ social security numbers, home addresses, phone numbers and emails. When our client merged with a partner, that information was easily transferred over because we utilized the surrogate key. My entry-level engineers caught on quickly and we later used it for our client to also track increases in employee performance.”
Common data modeling interview questions and answers
As you consider the following questions, try to format your answers using the STAR interview answer technique. This strategy helps you craft answers that illustrate your knowledge and qualifications through specific experiences.
Using the STAR method, discuss an applicable situation, identify the task you needed to complete, outline the actions you took and reveal the results of your efforts.
Here are five common interview questions about data modeling you may be asked during your interview:
What is data mart?
This data modeling interview question is vetting for a strong background in understanding and basics. Explaining the specifics to this question shows an attention to detail and a focused response exhibits a knowledge base that shows you appreciate the need to improve end-user response time. You may consider something like this:
Example: “For one of my first projects a client came to us needing a quicker way to access data at a low cost. I used data mart, a structure specific to data warehouses and a subset of them. It is a repository of summarized information focusing on a specific unit within a business or organization that is easily created. It saved our client money because it is more cost-effective than running a full data warehouse, and our client was able to easily access the data they frequently used. I often use it to effectively track merchandise or sales but only within a specific department of the entire structure.”
What is a Data Model?
A data model organizes different data elements and standardizes how they relate to one another and real-world entity properties. So logically then, data modeling is the process of creating those data models.
Data models are composed of entities, and entities are the objects and concepts whose data we want to track. They, in turn, become tables found in a database. Customers, products, manufacturers, and sellers are potential entities.
Each entity has attributesâdetails that the users want to track. For instance, a customerâs name is an attribute.
With that out of the way, letâs check out those data modeling interview questions!
 What is a Table?
A table consists of data stored in rows and columns. Columns, also known as fields, show data in vertical alignment. Rows also called a record or tuple, represent dataâs horizontal alignment.
Database normalization is the process of designing the database in such a way that it reduces data redundancy without sacrificing integrity.
Popular Data Modeling Interview Questions and Answers To Prepare For in 2022
We have split the interview questions into categories for beginners, intermediate, and advanced. Let us dive into these categories and help you start your data modeling journey!
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FAQ
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