Assume there is only one node with R rows. What is the theoretical time complexity of basic Cassandra operations?

More specifically, I want to know:

`key = item`

. I assume it to be`O(log(R))`

is it right?`key > item`

, i.e. slice. Will C* fetch all R rows to judge if the condition is met, which results in`O(R)`

? What about ordered rows?`key > 10 AND key < 12`

. Will C* first select all that matches`key > 10`

and then filter with`key < 12`

? Or C* will combine them into a single condition for query?