I think this question is based on classical thinking about database queries, which is not really how we do things today. A generation (or two) of software engineers were taught at the altar of correctness and integrity: you dont want the same $100,000 to be withdrawn twice. But today, if I ask Google, which is the most popular R&B artist in Seattle? and it tells me Symone Kamaria, how do I know that is correct? What does that question even mean? It’s no longer about correctness, it’s about value.
I have no inside knowledge of how Roon’s search algorithm works. But let me tell you a somewhat similar story: a few years ago I talked with people who ran a cloud-scale search engine about the database architecture. They told me, when you enter a search, they start a timer. Then they send the query, plus everything they know about you and your computer and location and time history and reputation and the color of your dog, to various information providers: not just the search engine but the advertising system, geography-based advertising, advertiser accounts, fraud detection… When the timer hits 10 milliseconds, the results from any of the providers that have replied in time goes into an algorithm, the search results and the ads are constructed, and sent out. If the advertising account status doesn’t respond in time, maybe an ad is displayed even though the advertiser’s budget is already exhausted. Timeliness trumps correctness.
How did R&B and Seattle and my search history and my age go into that result? AND or OR?
This is why I was sitting in a Frankfurt hotel, reading the British Guardian, and an ad for Canon zoom lenses from B&H Photo in New York appeared on the front page. Was it relevant at the time? Yes. Was it accurate? Huh?