The second one will be the most efficient. How much depends on how unique key1 is.
In the first case everything for the same key1 will be on the same partition. If it's not unique at all that will be very bad. In the second case the combo of key1 and key2 will decide what partition. If you don't ever have to find all key2 for a given key1 I don't see any reason to do case 1 > On 27 Dec 2016, at 16:42, Voytek Jarnot <voytek.jar...@gmail.com> wrote: > > Wondering if there's a difference when querying by primary key between the > two definitions below: > > primary key ((key1, key2, key3)) > primary key ((key1, key2), key3) > > In terms of read speed/efficiency... I don't have much of a reason otherwise > to prefer one setup over the other, so would prefer the most efficient for > querying. > > Thanks.
