Caching isn't great though. Pagetables are a trie, so it's max log log log time to prepend, append, or concatenate, and usually constant small for two of them

Caching isn't great though. Pagetables are a trie, so it's max log log log time to prepend, append, or concatenate, and usually constant small for two of them (but admittedly: you usually have to pick if you don't know how many arrays you want).