Append only is never that if you want any performance in rabdom access. You either get a block table or a tree, brother of which is naturally lock-free or zero

Append only is never that if you want any performance in rabdom access. You either get a block table or a tree, brother of which is naturally lock-free or zero-copy, even if it's a single pointer change. It can reduce concurrent access, sometimes, at the cost of extra consolidating rewrites.