> Most operations on clojure persistent data structures are an order of magnitude less efficient than they are on the mutable equivalents
It's not really clear what you mean by "order of magnitude" here. The notation you're using suggests that you're thinking in terms of asymptotic algorithmic resource requirements, which are most often characterized by polynomial degree; an order of magnitude ("factor of 10") is invisible in those terms.
But a factor of log n, while not invisible, is nearly so. If you're thinking in terms of polynomial degree, a factor of log n is literally an infinitesimal value - it's more than 0, but less than all positive real numbers.
It's not really clear what you mean by "order of magnitude" here. The notation you're using suggests that you're thinking in terms of asymptotic algorithmic resource requirements, which are most often characterized by polynomial degree; an order of magnitude ("factor of 10") is invisible in those terms.
But a factor of log n, while not invisible, is nearly so. If you're thinking in terms of polynomial degree, a factor of log n is literally an infinitesimal value - it's more than 0, but less than all positive real numbers.