Meet Hugo Kornelis, Execution Plan Expert.

Hugo Kornelis is a database consultant in the Netherlands. Here are a few of his sites that you might recognize:

• SQLServerFast.com – his useful and insightful blog
• The Execution Plan Reference – the only exhaustive, detailed explanation I’m aware of for every execution plan operator, well above and beyond Microsoft’s documentation
• Hugo’s execution plan classes
• YouTube search results because he’s given a lot of sessions on a lot of different channels
• SQLBits archive of his sessions – you can click on each one to watch free videos
• Hugo on LinkedIn

Because I travel a lot, I’ve had the pleasure of watching Hugo speak at conferences all over the world, most recently at Data Saturday Croatia. He’s very knowledgable, very humorous, and very humble, one of the most pleasant and down-to-earth people I’ve ever met.

He’s endlessly curious in a delightful, charming way. He doesn’t just wanna know everything about query plans, but when he’s talking to you, he wants to know everything about you, too, and he seems to find that just as interesting as he finds the query optimizer.

He also loves sharing, as evidenced by the huge volume of freely available material that I linked to above.

It’s hard to overstate just how much Hugo shares. Check out the columnstore index scan operator page on his Execution Plan Review, for example. It’s amazing, like way more detailed than what’s in the equivalent Microsoft documentation. That wasn’t a one-and-done page, either – that information has changed a lot over the years, and at the bottom of that page, Hugo even goes to the trouble of maintaining a change log of what he’s changed, right up until this month:

Just the change log alone on these pages is more information than I know about most of these plan operators. I learn something every time I visit one of these pages, and I’m reminded by how little I know – and simultaneously, how much Hugo knows.

Which is kind of a bummer.

Because Hugo is dying of leukemia.

Hugo has been documenting his treatments since the first awful 2022 surprise in the same friendly, interesting way that he always writes. A lot of us in the community have been following it closely, cheering him on, wearing Team Hugo shirts. Unfortunately, his post this week explains that he’s out of options, and his doctors are now treating the pain rather than the disease.

If you too have had the delightful pleasure of learning from Hugo – whether on his blog, his many conference sessions, his activities in the community, or just hanging out with him – now is your chance to thank him for his lifetime of dedication to the service of others. Read his last post, and read it again. As with all of his work, there’s a lot to absorb in there. Then thank him for his tireless work of sharing everything he’s learned along the way, and how he made you feel while he was doing it.