In my second or third year at Cal, I took the grad database class with Michael Stonebraker. Adam Sah pulled a little stunt for our final exam and invited Jim Gray to show up and sit in the front row. Stonebraker's reaction was mildly entertaining. Whoever you are, Jim Gray has probably forgotten more about relational database management systems than you ever knew. Except maybe for Hector Garcia-Molina. Ha ha, only serious.
Werner Vogels reports that Jim Gray went sailing recently and hasn't been heard from. I only had a micro-moment with Gray, but I'm with Vogels praying for his safe return.