Unreplicated MEMORY tables, prepared and cached statements, efficient DDL and sane indices, no contention or locking, no access from multiple sessions, some per

Unreplicated MEMORY tables, prepared and cached statements, efficient DDL and sane indices, no contention or locking, no access from multiple sessions, some performance tuning of InnoDB, ample resources, DB not stressed, no difference in pure network latency. MySQL's query optimizer/planner/parser perform a lot more "gyrations" than Redis or MemcacheDB do before finally reaching the point of touching the datastore to be read/written, even in the case of prepared statements. Their respective complexities are not really comparable.