Top 25 Database Design Interview Questions and Answers 2021


Database Design Interview Questions

When employers are looking for a database designer, they are careful to identify someone who is skilled in database design. No one would want the data of a company to be exposed to threats. Besides, effective execution of this role is essential to ensure that different operations and processes run smoothly.

People aspiring to fill the database design position must be familiar with the process of database design including stages, processes, and techniques involved. Besides, the right candidate must be aware of database-related technologies that can be implemented to enhance the operation of a database.

Job interview questions and answers for database design are very helpful when it comes to knowing what to expect. If you’re preparing for a database design interview, we’ve got you in mind. Below is a list of commonly asked questions and a sample of the best answer.

1. What is Database Design?

Database Design is the process of creating a structured data model for a database. This data model includes all of the logical and physical design options, as well as physical storage parameters, that are required to produce a design in a data description language, which can then be used to construct a database.

2. Why are You Interested in this Role?

I’m interested in this database design position because I believe my expertise will be useful in solving a database design and development issue at your organization in this capacity. I also see this as a chance for me to learn and develop these skills, which will help us both personally, professionally, and financially.

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3. What are the Roles of a Database Designer?

The database designer is in charge of creating the comprehensive database architecture, which includes tables, indexes, views, constraints, triggers, stored procedures, and other database-specific structures for storing, retrieving, and deleting permanent entities. The database designer’s responsibilities may also differ depending on the scale and complexity of the application development project as well as the type of permanent data management systems used.

4. What are the Qualities that a Database Designer Should Possess to be Effective?

Being an effective Database Designer necessarily requires humility and a desire to learn. This is someone who will relate to the team’s and the company’s overall success. This often includes doing assignments that aren’t part of the job description. It also entails being enthusiastic, dependable, dedicated, punctual, completing tasks on time, and doing work without being asked, while being able to work with persons of different personalities.

5. What Is the Logical Design of a Database?

The logical design process entails organizing data into a set of logical relationships known as entities and attributes. A block of data is represented by an entity. An entity typically maps to a table in relational databases. An attribute is a part of an entity that helps in defining the entity’s uniqueness.

6. What is the Structure of a Database?

Rather than putting all of the data in a list in a random order, a database provides a framework for the data to be organized. A database table is among the most common data structures. Rows and columns make up a database table. A two-dimensional array is yet another name for a database table.

7. What is a Logical Data Model?

A logical data model, also known as a logical schema, is a data model of a particular problem domain represented in terms of data structures such as relational tables and columns, object-oriented classes, or XML tags, or a specific database processing product or storage systems (physical data model).



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8. What is a Conceptual Data Model?

A conceptual schema is a high-level outline of a company’s informational requirements. It usually contains the most important ideas and their interconnections. The data model can be used to define the conceptual schema when a database system is applied, thus the name conceptual model, which is also known as the data model.

9. What is the Conceptual Design of a Database?

Conceptual design is the name given to this stage. An Entity-Relationship (ER) diagram or a UML class diagram is the end product of this stage. It’s a high-level data model for a particular area of application. It defines the relationships between various entities (objects, items).

10. What is the Physical Data Model?

A physical database model depicts all table configurations, including column names, data types, constraints, primary keys, foreign keys, and table relationships. A physical data model has the following characteristics: Both tables and columns should be defined. Relationships between tables are identified using foreign keys.

11. What are the Features of a Physical Data Model?

The features of a physical data model are:

  • Specification of all tables and columns
  • Use of foreign keys to identify relationships between tables
  • Denormalization can occur as a result of customer needs.
  • Due to physical considerations, the physical data model may vary significantly from the logical data model.
  • For each RDBMS, the physical data model would be different. The data type of a column, for example, can vary between MySQL and SQL Server.

12. What is the Difference Between Logical Data Model and Conceptual Data Model?

The differences between the logical data model and conceptual data model are:

  • Primary keys are present in a logical data model, but they are excluded in a conceptual data model.
  • All attributes are defined within an object in a logical data model, while in a conceptual data model, no attributes are defined.
  • In a logical data model, relationships between entities are defined using primary keys and foreign keys. The relationships in a conceptual data model are clearly defined, not classified, because we simply know that two entities are associated, but we don’t define which attributes are used.

13. What is the Conceptual Framework?

A conceptual framework is a versatile methodological tool that can be used in a variety of situations. It is used to organize concepts and create conceptual distinctions. Strong conceptual frameworks capture the concrete in an easy-to-remember and incorporate manner.

14. What’s the Role of a Schema in Database Design?

A schema helps to determine the form of a data structure and what types of data should go where. A schema can define database-level structures like tables and indexes, as well as data-level constraints like field types in databases (string, boolean, reference, etc.)

15. What are the features of Database language?

A database language may include features such as:

  • DBMS-specific Configuration and management of storage engine
  • Computations to modification of query results by computations, like summing, counting, averaging, grouping, sorting, and cross-referencing
  •  Constraint enforcement Application Programming Interface

16. What Database Relationships Do You Know?

There are three types of database relationships. These are:

  • One-to-one: One table that has a drawn relationship with another table that has columns that are identical with those of it.
  • One-to-many: Two tables having a primary and foreign key relation.
  • Many-to-many: Junction table having many tables related to many tables.

17. How would You Handle Data Loss During a Database Migration?

I would perform an assessment to determine whether the data loss was due to a one-time anomaly or a concern with the whole migration. Then, I would retrieve the latest backup that was performed immediately before the migration. I would also ensure to document the reasons for the loss and the solution implemented for future reference.

18. What’s your Process for Troubleshooting Database Problems?

To keep an eye on the database servers, I use a mix of manual and proactive monitoring. I review the reports on a daily basis to see if anybody has reported any performance issues or other issues. When I come across something that needs to be fixed, I start by diagnosing the signs and possible causes. Depending on my workload and the difficulty of the repair, I can assign the hands-on repair to a lower-level technician.

19. What Major Challenges Did You Face During Your Last Role? How Did You Handle It?

I was once in charge of performing a prototype migration as part of a data migration initiative. During the test, I discovered that some parts of our data had been lost or compromised. I tried to troubleshoot the problem in order to figure out why it was happening. I discovered that some systems were outdated and were getting lost in the file updates. Fortunately, I had downloaded a high-quality recovery program to restore these lost files, and I had taken care of the problem to ensure that the corruption and loss of these data files did not occur again.

20. Describe Your Daily Routine as a Database Designer?

A database designer has a dynamic daily routine but may expect to regularly carry out tasks such as to write programming codes, consolidate data, design online forms, program automated systems, create and enhance data models, design database storage systems, and troubleshoot and analyze data.

21. Describe briefly your Database Design Experience?

I have 5 years of experience working as a database designer. Over this period, I have performed a lead role in building databases for several organizations. This involved assigning roles, supervising design tasks, and ensuring that projects are delivered on time. Besides, I have worked with different databases. I will use my experience to make necessary improvements and scale database operations.

22. What kind of Strategies and Mindset is Required for this Role? Explain with example.

The top-down strategy and the bottom-up strategy are two different things to keep in mind for database design and development. Although these methods tend to be somewhat different, they both have the same goal: to use a framework by explaining all of the processes’ interactions. For example, there are some priorities to bear in mind when designing a relational database. Others are under the jurisdiction of the database designer, while others are dependent on other variables in the database system to differing degrees.

23. What is the Biggest Challenge that You Foresee in This Job?

The biggest challenge that I foresee in this job is having to make design compromises that are mostly prompted by conflicting interests such as conformity to design standards (design elegance), processing speed, and information needs. Whenever I’m faced with this challenge, I will ensure to employ expert judgment to ensure that all sides are balanced. My aim will be to ensure that my employer benefits from any design that I implement. I will aim to do that while ensuring that the database design in use is current and secure.

24. How Do You Stay Motivated at Work?

I make sure that I find a sense of purpose in everything that I do, which in turn has a major impact on my day-to-day life and job. I also plan ahead of time on all the tasks that I need to handle, prioritizing my workload, which is always quite rewarding. Being careful with the people that I surround myself with is also key. This is because, when you spend time with energized and motivated coworkers, you’ll be equally energized and inspired.

25. Describe a Time You Failed in this role and the Lesson You Learned

Barely two months after joining my current role, the database system malfunctioned. It was a scramble to either restore affected processes or, even worse, recover data. But after it all, I learned that the database, its host server, and the network should all have stringent protection and management routines and protocols in place to ensure minimum downtime. In the event that something goes wrong, the Database Designer must have a written crisis plan in place to immediately rebuild and reinstate the database.

Conclusion

If you want to ace your next database design interview, you will certainly need to know about databases and their design process. These questions and answers will help you familiarize with the question you should expect and the best way to respond to them. Also, while preparing for the interview, understand SQL’s place in the world. Being a technical-level expert in SQL is very important. Demonstrate that you have what it takes to perform the role of a database designer effectively and as expected. That way, you increase the chances of getting hired.

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