August 5, 2015 — Go inside PASS Summit 2015 session in this Q&A series with our presenters. In this interview, Kathi Kellenberger takes us inside her General Session, “Writing Technical Books”.

Q: Who is your favorite super-hero, and which SQL Server or BI super-power do you hope your session will give attendees?

Kathi: I haven’t been interested in super-heroes much as an adult, but of the super-heroes I know about, I would have to say Batman. Batman’s powers were not from some mutation, immigration from another planet, or exposure to radiation. His powers are based on the ability to come up with great ideas and the resources to turn those ideas into reality.

My session is “Writing Technical Books”, which is a rare super-power indeed. I have been writing for ten years, and my words have reached thousands of people around the world. When I think about how many people I have helped, I know that I have used my powers for good, not evil. This super-power is like a key to the world, and I hope that my session will inspire a few future authors to take that first step.

Q: What’s your origin story? How did you become interested in working with data, and how did you take that initial interest to the expert level?

Kathi: I have always loved logic and data. I remember being obsessed with math problems in grade school, usually working ahead until I completed my math textbook during Christmas break. I also spent hours looking at the library card catalog and encyclopedias. Luckily, I relate to people better now than I did back then!

Unfortunately, my interest in math and science led me to the wrong career. I spent 16 years in a field that I didn’t love before becoming a developer in 1997. I first touched SQL Server in 1998, but didn’t switch my focus until 2002, when a DBA job opened up at a law firm where I was working on a six-month programming project. I really wanted to work there, and thought that I would figure things out given a chance. That turned out to be a fantastic move for me. Not only was it a great place to work, but I finally found my niche.

I think that explaining what you know to someone else, be that writing, presenting, teaching, or blogging, really helps get anyone to the next level.

Q: What’s your favorite data solution’s secret power—the biggest strength that most people don’t really know about or use to full advantage?

Kathi: For SQL Server, it is T-SQL window functions. I have been speaking and writing on this topic for at least three years at many SQL Server events. I am always surprised that most people in the audience haven’t heard about them before or at least aren’t using them outside of ROW_NUMBER. By the way, I wrote a book, Expert T-SQL Window Functions, and recorded a Pluralsight course on this topic. The biggest advantage is that they make problems that are difficult to solve outside of cursors easier to solve. In some cases, you will also get better performance over older solutions.

Q: What about data’s biggest kryptonite or nemesis--the biggest mistake you see data professionals make?

Kathi: I would say blindly following index suggestions from SQL Server. I’ve been doing quite a bit of index tuning for my Linchpin People customers, and I am seeing tons of duplicate and overlapping indexes. The index suggestions might come from the execution plan, Database Tuning Advisor, or even the missing index DMVs, but you have to think about what is in place, not just create the suggested indexes.

Q: What still excites you or trips you up in the real world when working with SQL Server or BI?

Kathi: Twenty years ago, I dreamed of having a computer-focused career. I am still amazed that I get to work in such a fun and exciting field. Sometimes I can’t believe how well things have turned out for me after such a big midlife career switch. I am so grateful to be where I am today.

Q: What do you see as the next step after attending your session?

Kathi: After attending my session, I hope that the participants just start writing!

Check out our other Q&As with PASS Summit 2015 speakers.