Thank you Oskar. I think you may be missing the double parentheses in the first example - difference is between partition key of (key1, key2, key3) and (key1, key2). With that in mind, I believe your answer would be that the first example is more efficient?
Is this essentially a case of the coordinator node being able to exactly pinpoint a row (first example) vs the coordinator node pinpointing the partition and letting the partition-owning node refine down to the right row using the clustering key (key3 in the second example)? On Tue, Dec 27, 2016 at 10:06 AM, Oskar Kjellin <oskar.kjel...@gmail.com> wrote: > 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. >
