https://wimdy.works/tags/algorithms/Recent content in Algorithms on Brian FaustHugoen-USMon, 01 Jan 0001 00:00:00 +0000https://wimdy.works/thoughts/stop-scanning-every-tariff-row-for-every-service/Mon, 01 Jun 2026 00:00:00 +0000https://wimdy.works/thoughts/stop-scanning-every-tariff-row-for-every-service/<p>Scanning ten thousand tariff rows for each of a hundred candidate services means a million candidate-row visits before doing much interesting pricing. Most visits may end with the same answer: this row belongs to another service. Putting that loop behind a cache doesn&rsquo;t remove it.</p> <p>I changed this part of my private logistics engine by preparing an in-memory index of rows by carrier and service match. This wasn&rsquo;t a database index. The quote already had a restored runtime projection; the repeated work was inside that projection. The index moved some predicates out of the per-candidate loop, which made their preservation a correctness requirement rather than merely a performance detail.</p>