... unless it's something like a forgotten index in a database. Which can easily make a difference for a factor 10 or more. That's the problem with computing:

... unless it's something like a forgotten index in a database. Which can easily make a difference for a factor 10 or more. That's the problem with computing: Often you don't have a very good understanding if there's a good reason for the thing to be slow. Only if there is such a conceptual reason (like, you're solving a problem involving very many variables that must be optimized), you must start thinking if a different approach is in order.