One of my very first presentations was on isolation levels in SQL Server
Back in 2010, after an interview flop, I set myself on a mission to learn isolation levels backwards and forwards in SQL Server. I was surprised to find that I loved the topic, and I decided to start presenting about it.
I thought that the biggest problem with isolation levels was memorization: the names of the isolation levels are a little opaque, and it’s hard to build up a “picture” of the concepts and how they relate in your mind.
So I drew a picture! A poster, in fact.
I didn’t have much experience making digital art. I used a free program called Gimp, and muddled my way through the poster. That’s why the original is a .png file… I wasn’t even sure what format to use :)
Years later, the poster lives on
I guess this old poster had some charm, because I still get asked about it on Twitter. I’ve also heard that a printed copy of the poster was sighted in the SQL CAT lab. (Swoon!)
Is the poster still correct, all these years later?
Yes. There could absolutely be another interesting poster drawn when it comes to the nuances of isolation levels with In-Memory technology (or digging into any of these areas), but the basic isolation levels remain the same.
Thanks to Brent Ozar for permission to distribute the poster
When I co-founded Brent Ozar Unlimited, I brought this poster along with me into the company. Although I’m onto new adventures, I’ve posted it here with Brent’s permission. Thank you, Brent!