Actually, now that I think about it, step 1 isn't necessary. You don't actually need to shuffle the indexes since you always choose a random one anyway. It shou

Actually, now that I think about it, step 1 isn't necessary. You don't actually need to shuffle the indexes since you always choose a random one anyway. It should be enough to just do the swap on deletes in order to keep the integers contiguous. > I think you'll need a full table lock in case you're ever trying to do a remove and add at the same time Yeah, I think you need some sort of locking to ensure N can't be concurrently modified but I'm not a DB person, so I don't know how to go about that.