Of course, DBMS is a part of every application and system. Well, it might be for your software engineering interview; it might be for your database administrator interview, or something directly to do with data management, so there has to be this requirement to understand the concepts of DBMS Interview Questions. Getting that DBMS interview right calls for sturdy theoretical knowledge coupled with some practical experience in that area. Here's how best you can prepare and ace that interview.

1. DBMS Fundamentals
You can't engage in complicated relationships without knowing the basic things. Here are what you have to cover:

What is DBMS?: You must be aware of what it is, what are its functions, and the types of DBMS—hierarchical, network, relational, and object-oriented.

Database Models: Relational, object-oriented, and network models differ from one another. You must know them.
Schemas and Instances: You should know about schemas, instances, and how they are different from each other.
Data Independence: You should know about logical and physical data independence and what is the requirement for data independence.
DBMS Architecture: You should know what DBMS architecture is, which includes DBMS engine, database schema, query processor, etc.
2. Relational DBMS in Detail
RDBMS stands for Relational DBMS. It is one of the most common DBMS you'll come across in an interview. You should be well-equipped with:

Tables and Keys: Understand what primary keys, foreign keys, and candidate keys are, and how they make sure integrity is maintained within data.
Normalization: You have to explain normal forms; 1NF, 2NF, 3NF, BCNF, so that redundancy gets reduced, and the design of the database improves.
SQL Queries: Ability to create complex SQL queries such as joins (INNER JOIN, LEFT JOIN, RIGHT JOIN), subqueries, aggregate functions, GROUP BY, HAVING and ORDER BY clauses.
Indexing: Understand the types of indexing (single-level, multi-level) and how it benefits query performance.
Transactions and Concurrency Control: Knowledge on ACID properties and the techniques used in handling concurrency control and locking mechanisms.
3. Advanced DBMS Topics
Once you’re confident in the basics, move on to more advanced topics that might come up in interviews:

Normalization and De-normalization: Understand the trade-offs between normalization and denormalization, and when to apply each.
Database Design: Understand how to design a relational database from scratch. This includes knowing how to draw an ER diagram and how to translate that into relational tables.
SQL Performance Optimization: Learn how to write effective SQL queries, reduce execution time, and avoid common pitfalls such as unnecessary joins or nested queries.
Backup and Recovery: Understand the importance of data backup strategies and methods for recovering a database from failure.
Data Warehousing and OLAP: If data warehousing is covered during your interview, then surely you will be expected to know what OLAP is (Online Analytical Processing), how OLTP works (Online Transaction Processing), and in detail about data processing in a warehouse.
4. Practical Questions Preparations
You'll encounter practical problems for which solutions are required as well in an interview. You need to prepare yourself by

Practice Problem-Solving: Write a variety of DBMS problems, such as writing SQL queries, designing tables, and optimizing databases. LeetCode, HackerRank, and GeeksforGeeks are great places to look for DBMS problems.
Real-Life Scenarios: You might be asked how you could optimize a database for high transaction volume or how you could design a database for a specific business use case. Prepare to think critically and demonstrate how you can apply DBMS principles to solve real-world problems.
5. Go through Most Frequently Asked DBMS Interview Questions & Answers
Prepare for frequent interview questions related to the DBMS that often come around.

What is the difference between relational and non-relational database?
Why do we need indexing in DBMS?
How does normalization affect the performance of a database?
Explain different types of joins with examples.
What are ACID properties and why they are so important in database management?
What are different types of SQL constraints?
What is a database transaction, and how do you ensure consistency and integrity?
6. SQL Commands Awareness 
SQL is the heart of DBMS.  So, you must know all the simple and complex SQL commands: 

Simple Commands: SELECT, INSERT, UPDATE, DELETE, CREATE, ALTER, DROP, etc.
Complex Commands: UNION, INTERSECT, EXCEPT, CASE, HAVING, etc.
Join Types: INNER JOIN, LEFT JOIN, RIGHT JOIN, FULL OUTER JOIN, CROSS JOIN.
7. Mock Interviews and Practice
Preparing under mock interview conditions is the best way. You will feel confident, and you will be fully prepared to tackle questions in a very efficient manner.

Technical Mock Interviews
You can get a mentor or use online platforms which offer mock interview services. By practicing with peers or professionals, you will identify areas where you need improvement.
Behavioral Questions: Prepare questions based on experience with previous DBMS projects, problems that you faced and how you solved them.
Conclusion
This requires a blend of theoretical knowledge, practical skills, and critical thinking in the process of a DBMS interview. Begin with fundamental concepts and then expand your experience with work on advance topics like performance optimization, database design, and SQL. Practice constantly, take real-life scenarios, and make yourself ready for popular questions. With this approach, along with persistence, you're sure to ace your DBMS interview. Good luck!