great article, couple of questions -storing timestamp for each field (user:name) by default seems costly, timestamp can be stored on main key(e.g. user), curio

great article, couple of questions -storing timestamp for each field (user:name) by default seems costly, timestamp can be stored on main key(e.g. user), curious on the thinking.. -is timestamp 64bit? do we need miliseconds? -what is your sharding architecture, in terms of rage queries -are your global search indexes on this architecture