Let's say we have a simple CQL3 table

CREATE TABLE example (
    timestamp TIMESTAMP,
    data ASCII

And I need to mutate  (for example encrypt) column values in the "data" column for all rows.

What's the recommended approach to perform such migration programatically?

For me the general approach is:

1. Create another column family
2. extract a batch of records
3. for each extracted record, perform mutation, insert it in the new cf and delete from old one
4. repeat until source cf not empty

Is it correct approach and if yes, how to implement some kind of paging for the step 2?