25 Database Administrator Interview Questions & Answers
Below is a list of our Database Administrator interview questions. Click on any interview question to view our answer advice and answer examples. You may view 5 answer examples before our paywall loads. Afterwards, you'll be asked to upgrade to view the rest of our answers.
1. Explain the difference between a database manager and a data manager?
How to Answer
This could be classified as either a technical or general question. In either case, your answer is the same. You define each term, and then discuss the differences between them. The purpose of the question is to get you to talk about your perception of a database manager's role. Your answer should align with the duties and responsibilities outlined in the job description to which you applied.
Written by William Swansen on October 9th, 2020
Answer Example
"The difference between a database manager and data managers is fundamental. Data management is the process of using data to manage an operation, run a business, or solve an issue. Anybody can be a data manager if they use data to make decisions. Database management, on the other hand, is managing the underlying structure of the data, which is organized and stored in a database. Database managers don't use the data they manage for decision-making, except to define data tables, create queries, or when working with other database management tools."
Written by William Swansen on October 9th, 2020
2. Can you explain what ODBC is?
How to Answer
This is a technical question. When answering technical questions, you may want to ask clarifying questions. This will establish your credibility and knowledge in this area and allow you to tweak your answer due to the interviewer changing the questions' parameters. Another way to accomplish this is to start your answer with a statement about your assumption of what the interviewer is asking.
For exampl: "When you say ODBC, I assume you're talking about Open Database Connectivity. This is a method used by applications to communicate with the database. Another term for these is APIs. By creating APIs or ODBCs for their database, database developers make it easy for application developers to create interfaces to the database and easily access the data. Each type of database has its own unique ODBC."
Written by William Swansen on October 9th, 2020
Answer Example
"When you say ODBC, I assume you're talking about Open Database Connectivity. This is a method used by applications to communicate with the database. Another term for these is APIs. By creating APIs or ODBCs for their database, database developers make it easy for application developers to create interfaces to the database and easily access the data. Each type of database has its own unique ODBC."
Written by William Swansen on October 9th, 2020
3. Do you have experience with on-premises databases, cloud databases or both?
How to Answer
In today's technology environment, IT infrastructures can be located in various settings, including on-premises, hosted by a third party, or in the cloud. As a qualified database administrator, you should be able to manage the database in each of these environments. This requires knowledge of the differences between these infrastructures, how they impact the database's performance and any security issues you need to be aware of.
Written by William Swansen on October 9th, 2020
Answer Example
"I have direct experience managing databases both on-premise and in the cloud. I have also managed databases that are hosted at third-party data centers. While the fundamentals of database administration are the same in all three of these scenarios, some other issues should be considered. These include lag-time, security, and how to back up the database between the two sites. But again, I'm familiar with this and can easily accomplish this task."
Written by William Swansen on October 9th, 2020
4. What types of databases do you work with?
How to Answer
The purpose of this question is to gain a better understanding of your background. There are many different types of databases you can administer. The interviewer is attempting to determine if you have direct experience working with the type of databases they use in their organization. The research you perform before the interview should indicate the type of databases they use. Your answer should either demonstrate that you have experience with these or discuss how you can adapt to their databases using your experience managing other types.
Written by William Swansen on October 9th, 2020
Answer Example
"The majority of my experience has been in administrating Microsoft SQL Server databases. These are the most common in this industry, and I believe, are the ones that your organization uses. However, I have managed several other different types of databases, including Oracle and MongoDB. I pride myself on being able to transfer my administrative skills to different types of databases by simply learning a new command structure and characteristics."
Written by William Swansen on October 9th, 2020
5. What about data fascinates you?
How to Answer
This is another general question seeking to understand more about your background. At this point in the interview, you have been asked this question in several different forms. Remember that the interviewer will ask you similar questions throughout the interview to correlate your answers and ensure that you are consistent. You should answer all the questions honestly, briefly, and directly to achieve this.
Written by William Swansen on October 9th, 2020
Answer Example
"What fascinates me about data is how it can be used to make informed decisions. Having the right information at the right time helps you to make the right choices. The key to this is accessing the information when you need it. This is the function of a database. The other thing that fascinates me is that individuals can make different decisions using this same data. This is why I am also fascinated by artificial intelligence, which would standardize the decisions made using specific data sets."
Written by William Swansen on October 9th, 2020
6. What are the different modes of mounting a database with a parallel server?
How to Answer
This is an operational question. You will recall that operational questions, like technical questions, should be answered briefly and directly. You should also anticipate follow-up questions. Keep in mind that operational questions help the interviewer understand how you go about doing this job. This will help you craft your answer appropriately.
Written by William Swansen on October 9th, 2020
Answer Example
"There are two different modes you can use to mount a database with a parallel server. The first is the exclusive mode. This only allows one instance to mount a database. The second is the parallel mode. This mode allows other instances to mount the database at the same time. However, to use the parallel mode, the first instance must be launched in parallel."
Written by William Swansen on October 9th, 2020
7. Are you a development DBA or a production DBA?
How to Answer
The purpose of this question is to determine what type of database administration work you do or are capable of doing. As a DBA, you may have performed to jobs described by both of these titles. However, when answering this question, you should identify the title listed in the job posting. The exception to this would be if the job posting indicated that you would be doing tasks related to both of these different titles.
Written by William Swansen on October 9th, 2020
Answer Example
"Since the job posting I responded to was for a development database administrator, that is the role I would like to perform. However, in my previous positions, I have functioned as a production DBA, so I'm capable of doing both of these jobs. Having a strong background in development helps me in my production role when managing a database. Conversely, since I have experience administrating production databases, I know how to design a database to optimize its performance and ease of use."
Written by William Swansen on October 9th, 2020
8. What is normalization? Explain different levels of normalization?
How to Answer
This is another technical question. During an interview for a database administrator position, the interviewer will ask different types of questions and randomly switch between general, technical. Operational and behavioral questions. You can prepare for these by doing your research before the interview and practicing questions like these. Remember to answer the questions appropriately, according to their type.
Written by William Swansen on October 9th, 2020
Answer Example
"Normalization is a technique used by database administrators to reduce the redundancy of the data and eliminate any characteristics that impede the database's performance. Normalization is accomplished by separating the tables into individual smaller tables and using keys to relate the data. There are currently six levels of Normalization, including one through five normal forms and the Boyce-Codd Normal Form. There is a seventh (6NF) proposed. Each level uses a different set of rules to normalize the data."
Written by William Swansen on October 9th, 2020
9. How do you implement one to one, one to many, and many to many relationships while designing tables?
How to Answer
You probably recognize this as an operational question. Operational questions help the interviewer understand how you go about performing the duties associated with this role. Like technical questions, operational questions should be answered directly and briefly. You should also be prepared for follow-up questions.
Written by William Swansen on October 9th, 2020
Answer Example
"One-to-one relationships are defined as one record in a table being associated with one and only one record in another table. One-to-many relationships are established by associating a single record in one table with multiple records in another table. This requires the use of primary and foreign keys. Many-to-many relationships associate several records in one table with several records in another table. An example of this is a table full of customer names associated with a table full of products they can purchase. Again the use of primary and foreign keys as required. This type of relationship is also facilitated through the use of a join table."
Written by William Swansen on October 9th, 2020
10. Tell me your most successful program, project, or whatever you worked on that you were most proud of at your last job?
How to Answer
This is an interesting question in that it allows you to brag about your past accomplishments. When preparing to answer this type of question, you should use a program, project, or accomplishments related to the job for which you are interviewing. This will demonstrate to the interviewer that you can solve problems or accomplish objectives that are the same as those they have and for which they need to hire someone.
Written by William Swansen on October 9th, 2020
Answer Example
"Probably the accomplishment I am most proud of in my career was during my last position. The systems I was working on were used for online transaction processing or OLTP. There was a large volume of transactions, and the response time was extremely slow. My team and I investigated this and determined the tables' structure required multiple and repetitive queries for the data needed to complete the transactions. We restructured the tables, which resulted in a 60% decrease in processing time. This created a better customer experience and resulted in a 25% increase in sales during the next quarter."
Written by William Swansen on October 9th, 2020
11. Why did you choose to apply to our company when there are so many other opportunities for someone with your skills and experience?
How to Answer
This is another general question seeking to understand why you want to work for this organization. When responding to this question, you should discuss the organization's qualities and the contributions you can make. Inappropriate answers include the salary they are offering, benefits, vacation time, or other perks associated with the position.
Written by William Swansen on October 9th, 2020
Answer Example
"When I began searching for my next position, I identified several companies which had characteristics and opportunities I was interested in. I elected to apply for this position because it will provide me with challenges and offer me the opportunity for growth. I am also passionate about the type of work you do and believe that my skills and experience can contribute to improvements and how you manage your data. This will result in personal growth for me and organizational growth for you."
Written by William Swansen on October 9th, 2020
12. What excites you about this position?
How to Answer
This is another general question which the interviewer may ask any time during the interview. The purpose of this question is to find out about your passion for the job and the organization. By the time you arrive at an interview, your qualifications for the job have already been established. The purpose of the interview is to get to know you as a person and find out how well you will fit into the organization. This question will help the interviewer to determine this.
Written by William Swansen on October 9th, 2020
Answer Example
"As I mentioned earlier, I love working as a database administrator. This position will let me expand my skills while teaching others how to effectively manage a complex database. The other thing I like about this role is the organization. You have a reputation for innovation, collaboration, and creating a work ecosystem where everybody's opinion matters. This is the type of environment that I thrive in and can contribute to."
Written by William Swansen on October 9th, 2020
13. Explain the difference between explicit and implicit lock?
How to Answer
Another technical question asking you to compare two related but different terms. As a database administrator, you should know the differenced between terms like these. This knowledge helps you better organize the data into tables, create efficient queries, and manage database operations effectively.
Written by William Swansen on October 9th, 2020
Answer Example
"Locks are used to ensure that data is not duplicated or deleted during read and write operations. Implicit locks obtain access rights to the data as needed by the application. Explicit locking obtains exclusive access to the resources before initiating an operation to prevent other sessions from modifying the data required by the application."
Written by William Swansen on October 9th, 2020
14. Tell me about your education relating to database management?
How to Answer
This is a typical opening question during an interview. The interviewer will ask you a general question about your background to begin the conversation, learn more about you, and collect some information they can use for other questions during the interview. Questions of this nature provide you the opportunity to guide the interview in a direction with which you are comfortable and prepared.
Written by William Swansen on October 9th, 2020
Answer Example
"My formal education and subsequent studies have prepared me for a career in database management. As an undergraduate, I majored in computer science, exploring all the various disciplines within the field. I opted for database management because it was suited for my skills, incorporated several aspects of IT operations, and is at the core of how information technology is used to manage a business. It is also a practice that virtually every organization uses, so it provides me with career security."
Written by William Swansen on October 9th, 2020
15. What is a checkpoint?
How to Answer
This technical question is asking about another process used in your role as a database administrator. At this point in the interview, you may be getting a little impatient by having to answer all of these technical questions. The key to a successful interview is to remain calm and respond to the questions consistently. Every interviewer is different, and their style may not always match yours. However, by being patient, you will demonstrate your ability to remain calm in stressful situations. This is a key trait database administrators should possess.
Written by William Swansen on October 9th, 2020
Answer Example
"Checkpoints are used in many computer operations. Their primary purpose is to create a backup of the data. The backups can be used to restore the data in the case of a failure or undo an update that was not successful. Database administrators can define when the checkpoints occur and what data they save."
Written by William Swansen on October 9th, 2020
16. What is a tablespace?
How to Answer
Yet another technical question. The best way to prepare for an interview with a large number of technical questions is to review the terms, processes, and operations typical of your profession. Practicing interview questions similar to these is another way to prepare and be ready for anything you may be asked. The best way to practice these questions is to state both the question and your answer out loud. This creates a type of muscle memory that will make you more comfortable during the interview.
Written by William Swansen on October 9th, 2020
Answer Example
"Tablespaces are the logical storage units used by a database to store all the data. A tablespace consists of one or more data files, which are physical structures tailored to the type operating system the database is running on."
Written by William Swansen on October 9th, 2020
17. What is written in the redo log file?
How to Answer
This is another follow-up question. In this case, you didn't mention the redo log in your answer. However, instance recovery depends on the redo log. By asking multiple questions about a single topic, the interviewer is indicating that they may have had issues with this in the past and are looking for a candidate who has an in-depth understanding of this topic and can implement it properly if hired. Once you recognize that the interviewer has a specific interest in a topic, you should expand your answers to further demonstrate your knowledge of and qualifications in this area.
Written by William Swansen on October 9th, 2020
Answer Example
"One of the crucial structures in a database related to recovery operations is the redo log. The redo log consists of two or more files that store all the changes made to the database as they occur. It functions similar to a cache, except that the changes are preserved for a time designated by the administrator. When an instance failure occurs, and the instance recovery process is initiated, it queries the redo log to verify what transactions have not been recorded in the database."
Written by William Swansen on October 9th, 2020
18. What is instance recovery?
How to Answer
This is a follow-up to the previous question. Since you mentioned instance recovery in your last answer, the interviewer is asking a follow-up question to explore the topic in more detail. Technical questions and follow-up questions are meant to test your qualifications and confirm your knowledge of the processes and procedures used in this role. Follow-up questions are answered similarly to technical questions.
Written by William Swansen on October 9th, 2020
Answer Example
"Instance recovery is the process of bringing back transactions which have not been written into the database at the moment of an instance failure. This ensures that no date is lost or duplicated in the database. Instance recoveries may be initiated due to hardware issues, power interruptions, or network outages."
Written by William Swansen on October 9th, 2020
19. What is the job of SMON, PMON processes?
How to Answer
No doubt, you have already recognized this is a technical question. This question's structure asks you to first define and then compare two different processes used in the role of a database administrator. To enhance your answer, you may want to also provide an example of how each of these is used in your work. Again, remember to keep your answer brief and to the point added to separate follow-up questions.
Written by William Swansen on October 9th, 2020
Answer Example
"SMON stands for system monitor and performs a recovery after an instance failure while monitoring temporary segments and extents. PMON stands for process monitor and is responsible for recovering a process when a user process fails. It also performs cleanup of the process. Both of these function in the background."
Written by William Swansen on October 9th, 2020
20. What information is stored in the control file?
How to Answer
This is another technical question. You can easily recognize a technical question because the asks you to define an element, terms, or process used in the job. Remember to answer technical questions briefly and directly, thereby providing the interviewer the opportunity to either move on or ask a follow-up question.
Written by William Swansen on October 9th, 2020
Answer Example
"A control file defines the structure of a database. Elements it contains include the database's name, the locations of files associated with the database, and log files. It also contains records about when the database was created and subsequently updated."
Written by William Swansen on October 9th, 2020
21. When did you know you wanted to be a Database Administrator?
How to Answer
This question is similar to several other questions you have already been asked. Interviewers will ask similar questions throughout the interview to correlate your answers and make sure you are consistent. When answering questions, you should always be truthful and base your answers on your experience and the job for which you are interviewing. This will help you be consistent throughout the interview and provide the interviewer with a true picture of your qualifications.
Written by William Swansen on October 9th, 2020
Answer Example
"I believe I first knew that I wanted to be a database administrator during one of my advanced coding classes. It dawned on me that I enjoyed this type of work, managing large amounts of data by creating innovative table structures and effective querries. The work seemed to come naturally to me, and I enjoyed it. It proves the point that if you can make money doing something you enjoy, you will never work a day in your life."
Written by William Swansen on October 9th, 2020
22. Tell me about your most memorable experience during yourundergrad education?
How to Answer
This is another general question you're likely to be asked at any time during the interview. Questions like this help the interviewer learn more about your background or act as a bridge between technical and operational questions. General questions also provide you the opportunity to demonstrate your communication style. Organizations prefer to hire people who communicate effectively since this is a large part of just about anybody's job.
Written by William Swansen on October 9th, 2020
Answer Example
"The highlight of my undergraduate experience was attending a lecture presented by Larry Ellison. As the founder of Oracle and one of the IT industry's most notable individuals, it was fascinating to hear him speak and gain some insight into his views concerning databases, IT infrastructures, and the computer industry. I especially enjoyed hearing about his vision for the future of the industry and what type of products and technologies we can anticipate going forward."
Written by William Swansen on October 9th, 2020
23. What are user-defined database functions, and when should you go for them?
How to Answer
You may have already recognized this as another technical question. As a database administrator, you can anticipate a great many technical questions during the interview. The other type of questions you will be asked are operational questions, which help the interviewer to understand how you go about doing your job. Remember to keep your answer to both types of questions brief and to the point. You should anticipate follow-up questions any time you provide an answer.
Written by William Swansen on October 9th, 2020
Answer Example
"User-defined database functions are created to perform a specific task designated by the programmer. They are used as a mechanism for extending the functionality of the database. The function is evaluated in a standard query language (SQL) statement. An example is creating a function that will take an array of elements and return the sum for all of them."
Written by William Swansen on October 9th, 2020
24. What is the difference between a primary key and a unique key?
How to Answer
This is your first technical question. Technical questions ask you to define terms or processes used in your profession. The best way to respond to a technical question is to first define the term, describe how it is used, and possibly provide an example. Your answer should be brief and to the point. This enables interviewers to ask follow-up questions if they want to explore the topic in more detail or have a specific interest in it.
Written by William Swansen on October 9th, 2020
Answer Example
"The main difference between a primary and a unique key is that a primary key will accept no null values, whereas a unique key will accept just one null value. Additionally, the primary key will create a clustered index automatically when it is defined, whereas the unique key generates a non-clustered index."
Written by William Swansen on October 9th, 2020
25. Why are you the best person for this position?
How to Answer
This is another general question which you are likely to be asked early in the interview. This is an opportunity for you to respond with your 'elevator pitch.' This is a 30 to 60 second summary of your skills, experience, and talents. It should contain information about what you have done, what you are currently doing, and what you would like to do next. It would be best if you had composed and rehearsed this in preparation for the interview.
Written by William Swansen on October 9th, 2020
Answer Example
"I believe I am the best person for this job based on my experience, skills, and future career aspirations. I have a great deal of experience managing databases of all different types and sizes, with different content. I'm adept at writing scripts to expedite information retrieval and create efficient and effective data structures. I've done this in many roles with organizations similar to yours. I'm attracted to this job because it will allow me to further develop my skills while assisting your organization to continue to grow and be successful."
Written by William Swansen on October 9th, 2020