One thing to remember when conducting an interview is that the interviewer is also being examined by the interviewees. The French writer Voltaire said, “Judge a man by his questions rather than by his answers.” So, when we have the task of interviewing people, we should endeavor to ask good questions so that not only can we accurately assess the candidate, but also so that they can get a glimpse of our thinking and our company.
In my opinion, the best types of questions are not “true/false” or “yes/no”. But rather, the best questions are the ones that get people talking and helping the interviewer to understand their thinking process and communication style. In a previous post (https://sqlbadboy.wordpress.com/2013/07/31/interview-questions-part-1/), I dealt with general interview questions that I like to ask to all database professionals. However, in this post I am going to focus on questions I normally ask specifically to database administrators.
Interview questions for database administrators
What is your current database environment like?
- Really, for any “good” DBA this question should be super easy. However, if someone can’t describe their current environment in terms of the number of servers and databases, sizes of databases, and the maintenance performed, are they really taking care of their database environment?
What are the most important tasks for a DBA to handle?
- This is a general question and can have varying answers. But at the very least, you should hear them speak about backups, monitoring job and application failures (i.e. logs), performance optimization and indexing, checking database integrity, and security.
What are the basic functions of the system databases (i.e. master, msdb, model, tempdb)?
- This question should be answered correctly by anyone who considers themselves a DBA (http://technet.microsoft.com/en-us/library/ms178028.aspx).
How can SQL Server be used with Windows clustering, database mirroring, log shipping, replication, and AlwaysOn technologies?
- I ask this question to see if they understand some of the more advanced concepts of being a database administrator, which deal with high availability and disaster recovery.
If a user perceives that a database is slow, what steps do you take to troubleshoot the issue?
- As long as their answer seems logical and is along the lines of using baselines, monitoring tools, DMVs, performance counters, wait stats, etc., I will be fine with that. However, if the first thing they say is that they will restart SQL services or delete data, a red flag goes off.
How can using PowerShell make a DBA’s life easier?
- This question is intended to see if they are a progressive DBA. The use of PowerShell has really increased in the technology community in the past few years, and I think it is important for DBA’s to keep up with that.
Draw a picture of how the SQL Server stack works (i.e. Databases, Data Marts, Data Warehouses, Cubes, Integration Services, and Reporting Services).
- Since a lot of DBA’s support the whole stack, it is important that they understand the whole picture and be able to explain that simply to someone else.
Now, this is by no means an exhaustive list of questions that I may ask someone applying for a database administrator’s job. But rather, this is just a list of starter questions. And depending on how an applicant will answer, it may lead me to a follow-up question in that area. In my next post, I will focus on questions to ask business intelligence developers.