[Admins]

I never use begin/commits, it just adds more hassle. What can speed up stuff is to do several inserts with the same query. For optimization it's good to not store data which you don't need to store, e.g. don't store if the value is empty anyway and you don't have previous entries for this key (I've seen bad examples on several bigger servers), and you need to add indices to make the lookup fast. One thing that is often speeding up queries is to only update the columns which you want to update, because updating a key is much much slower because it needs to update the index too.