Reducing the round trips to the DB or doing calculations when you need them need no knowledge AT ALL of algos.
Saying it's "I/O" is so abstract and ultimately useless. A simple SQL query could hold a dark secret of a missing index on a table with a billion rows. Yes, that's technically I/O, but for today's programming that's so obtusely abstract it's pointless calling it that. It's a couple of lines of code that all the algo knowledge in the world won't have stopped the problem happening.
It's simply common sense. This is what we're trying to tell you. This is what we're trying to explain to you. Performance problems are almost always unintended consequences rather than "I'll suck it and see". Knowing how to implement the sort yourself won't save you, you have to spot the problem first, which is the hard part.
Basic multiplication is not algos. Knowing that a 100 loops of a thousand loops of a 1ms method is bad doesn't require magical knowledge. Algorithms was always a smoke and mirror trick, the ones you need are usually already in your language written much better than you could and the rest simply hides the truth that performance is mainly down to unexpected I/O bottlenecks usually buried under many layers of abstraction (SQL) or the occasional loop within a loop hidden in a long call stack.
Saying it's "I/O" is so abstract and ultimately useless. A simple SQL query could hold a dark secret of a missing index on a table with a billion rows. Yes, that's technically I/O, but for today's programming that's so obtusely abstract it's pointless calling it that. It's a couple of lines of code that all the algo knowledge in the world won't have stopped the problem happening.
It's simply common sense. This is what we're trying to tell you. This is what we're trying to explain to you. Performance problems are almost always unintended consequences rather than "I'll suck it and see". Knowing how to implement the sort yourself won't save you, you have to spot the problem first, which is the hard part.
Basic multiplication is not algos. Knowing that a 100 loops of a thousand loops of a 1ms method is bad doesn't require magical knowledge. Algorithms was always a smoke and mirror trick, the ones you need are usually already in your language written much better than you could and the rest simply hides the truth that performance is mainly down to unexpected I/O bottlenecks usually buried under many layers of abstraction (SQL) or the occasional loop within a loop hidden in a long call stack.