I think we are using "problem" in two different ways that are each reasonable but are not the same: 1. something that happens and needs to be fixed, and 2. some

I think we are using "problem" in two different ways that are each reasonable but are not the same: 1. something that happens and needs to be fixed, and 2. something that is fundamental and difficult to overcome. In my comment up-thread, I meant more the #2 definition, but you clearly mean the #1 definition. I spent a number of years working on a Rails application that used ActiveRecord and which accrued quite a large set of data. In that job, I fixed a whole bunch of N+1 problems, and wrote sql queries with complex joins before the nicer query-builder arel syntax was implemented. I was a pretty vocal critic of AR at my company because of these sorts of headaches (though I was much happier post-arel). But these were all very surmountable problems, the libraries had the capabilities necessary to fix the problems, and as our team matured in our intuition for our data model and size, we ran into these things less and less. In other words, I see this as very much a #1 type of problem rather than a #2 type of problem. A good analogy seems to be n^2 algorithms. In much the same way, you can write one of those and it works fine for awhile, but then one day you may find that your data has grown enough that it no longer works, and it may be very mysterious what happened. But with some experience and work, you can figure it out and probably fix it. And as you gain experience, you can more wisely decide whether to avoid the n^2 algorithm from the start, or whether it will work fine for your data size.