SQL Interview: Starting a new series of blog posts

SQL Interview: Starting a new series of blog posts

Many clients hire me to carry out job interviews on their behalf. If they’re hiring someone for a data-related role, they want to make sure they’re hiring the right person. That usually means two things:

  • The person will fit well within the culture of the organization
  • The person is technically competent.

I can’t help with the first one. If I’ve worked with the client for a long time, I might have a pretty good idea but ultimately, that’s something the client needs to decide.

But I’m well-placed to help them with the second part, and that’s the part that the client often doesn’t feel they can do well themselves.

Note: It’s not the point of this post, but if you’d like to get me involved in your interviews, please just reach out.

Technical interviews

For the technical interviews, it’s not just a basic knowledge test. I aim to work out two things:

  • Does the candidate actually understand the technology that they claim to, and at which level of expertise?
  • How well do they approach problems that they don’t immediately know the answer to?

For their knowledge understanding, I’ll start with fairly easy questions so they get comfortable, then use increasing depth to probe different areas, to judge their real understanding in those areas.

For the problem solving, I’ll give them scenarios, ask if they have any immediate ideas on potential solutions, then dive into how they’d try to solve it. They can tell me what they’d check, and I tell them what they would have found if they did.

Problem Solving Ability

I’m keen to see how logically they think and how they approach problem solving. I wish I could say that the ability to think logically can easily be learned, but I’m afraid my experience tells me that’s just not true.

Back when I worked for HP in the mid 80’s, they sent us on a Kepner-Tregoe course on logical troubleshooting. I’m sure it seemed like a great idea, and the course was well constructed. But the people in my class who could logically troubleshoot at the start, were the same ones who could do it at the end. It’s great to have a core methodology. But to me, it’s all about the ability to think logically, and that takes longer than a week to learn. However, it’s a critical skill when getting to the bottom of problems.

Blog Series

I decided to make a blog post series that covers a lot of questions that check core understanding of SQL Server topics. I’ll include questions at different levels, and on a variety of SQL Server related topics.

I’m not talking about tricky or gotcha questions, or anything like exam prep questions. Just checks on core understanding.

BTW: I’ve added a new category called SQL Interview. So you can easily find any/all of them amongst my other posts by using the category filter on the blog. I’ve also got a series of Business Intelligence questions (focussing on Power BI, Tabular data models, Data Factory, etc.) being prepared.

I hope you enjoy reading these. Nothing is ever absolute in this industry, so if you disagree with any of them, feel free to comment and say why.

2021-03-18