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.)