> Ages ago I had a conversation with a coworker about why was it that if databases collect statistics for optimizations, that data structures in programming lan

> Ages ago I had a conversation with a coworker about why was it that if databases collect statistics for optimizations, that data structures in programming languages don't do the same thing? Lus tables in LuaJIT, Hack arrays, and JavaScript arrays can use different representations depending on what is stored in them. NYU’s SETL project also did some work on automatically identifying what data structure should be used. IBM’s Hermes project was also working on this; I’m not sure whether they shipped it.