Spending some time today optimizing confirmation queries. They aren't too bad on the big box, but thrashing is a problem on the mini. There are several ways the queries can be vectorized within a block. I worked up several options in the spring but never got them fully evaluated. ASIO fan-out within a block looks like it will be suboptimal and is also much more complex. c++17 std::transform(par_unseq, ...) in up to three subqueries is working well.