Problem
We are hiring a new Senior DBA and would like to know what questions to ask to find the best candidate?
Solution
The interview process is not always easy for either the interviewer or interviewee. But to find the best candidate, there is no better way than asking the right questions. To me, for a Senior DBA, answers to technical questions are less important then technical experience, which itself is less important than technical capability, which can be best exposed via non-technical (or semi-technical) questions.
Here are 10 of my favorite questions and they are targeting three DBA traits: attitude, ambition, and passion
- What is the current major technical challenge in your work? Any thoughts on addressing this challenge?
If a candidate has no idea of any current challenge in his/her work, I doubt whether the candidate has ever put any efforts to his/her work and whether the candidate tries to improve him/herself via his/her daily work. For a Senior DBA, one untold requirement is to keep improving technical skills that may help improve the company’s bottom line.
- In your DBA career, can you tell me one or two achievements you are really proud of?
To be a successful DBA, there is one element that cannot be missing, PASSION for being a DBA. Achievements can be big or small, but a passionate DBA will never forget the achievement to which she/he has dedicated passion and enthusiasm and for which she/he has gone through the pain and toil to accomplish.
- Can you share some lessons you have learned as a DBA, what can you tell me?
I personally do not believe that a person can be a senior DBA without ever making one or two mistakes in a production environment. Actually, my personal experience is that one will become mature immediately even when making a single production mistake that scared you so much that you wish time could be reversed. This question will expose a candidate’s attitude towards the DBA work and how the candidate grows professionally out of the mistakes.
- If you are going to build a tool to manage your database environment, what features should this tool have and why?
In some perspective, we are only as good / capable as the tools we are using. For a Senior DBA, I expect one to come up with a list of tools that she/he will use to enhance his/her productivity to handle the daily work.
- Can you give one or two examples that can explain your database administration habits or style?
This is a fun question, but it can also expose a candidate’s maturity or administration culture fit to your existing team.
Use myself as an example, one of my administration habits is that when I write a stored procedure (SP) to do some specific work, whenever possible, I always like to have a parameter called @Debug for this SP. When @Debug=1, the SP will generate the actual T-SQL statements that I can copy and paste to a new SSMS window to run directly. If @Debug=0, those generated T-SQL statements will be executed automatically inside the SP. This will help me, at some time, to review the code before executing them.
- If you are hired to evaluate the quality of my current DBA team’s work, what/where will you look?
This is a tough question yet a good one to check a candidate’s experience and knowledge. To me, working with 20 to 30 production server instances is totally different from working with 200+ instances. Also working with databases sized less than 50GB vs. 500GB is different as well. To answer this question, if I were the candidate, I would ask about the current environment first before I can make any attempt to answer the question.
- Do you follow any SQL Server MVPs and if so, can you give me one or two names and why you follow them?
Continued learning is a must, and these days learning usually consists of reading various blogs/articles or watching technical videos. If a senior DBA does not have one “idol” in his/her mind, it would sound unbelievable to me. Personally, I have learned a lot from Itzik Ben-Gan on advanced T-SQL techniques and from Paul Randal about SQL Server internals, and also from numerous other people in the SQL Server community on various topics.
- If you are required to learn something technical to enhance your DBA skills, what are you going to learn and why?
This question may assist to identify whether a candidate can be a thought-leader. If you know what to do, yet do not know how to do it because of the lack of that skill or knowledge, it usually means you love thinking beyond your comfortable zone, and to me, a good idea usually is half the solution. If you know what to do and also know what to learn to be able to do it, you will succeed sooner or later.
- Have you ever encountered a SQL Server bug, if so what?
This question is good to check a candidate’s experience and persistence. As a DBA, if you have not encountered any SQL Server bug, it means either you have not worked with SQL Server long enough or when you encounter a problem you didn’t try to understand the root cause of the problem.
- What criteria do you use to judge if a DBA is a junior, intermediate or senior DBA?
This is a fun question too. So I’d like to answer this in a fun way (yet still serious).
- Junior DBA = she/he does not know what she/he knows. In others words, she/he thinks she/he knows, but actually she/he does not thoroughly know.
- Intermediate DBA = she/he knows what she/he knows.
- Senior DBA = she/he knows what she/he does not know.
Next Steps
You can read other interesting interview questions below:
