Victory! An operator in #Draupnir with unexpectedly quadratic behavior is now down to loglinear... as Knuth intended. 10min on a beefy desktop -> under 2 min on a substantially less beefy laptop. I knew this crude versioning extension for BTrees was going to have O(N) seek time, but expected the common case to be closer to the usual O(log N). This particular scenario ended up triggering the worst case behavior nearly every time. Silly me. #PerformanceOptimization