Steinar H. Gunderson: MySQL hypergraph optimizer

MySQL released (well, flipped the default compilation flag for) the
hypergraph join optimizer in the community builds; this was the main project
I started and worked on while I was there, so it’s nice to see even though
it’s been default in e.g. their cloud column store for a long time. You can read
their blog post
(though beware, likely-LLM text ahead).

(The cost model improvements and TPC-DS benchmarking are from after my time.)