Just wanted to learn Cassandra and trying to convert RDBMS design to Canssandra.
Considered my app is being deployed in multiple Data centers.

DB Design :

           A) CF : USER
                  1) email_id - primary key
                  2) fullname
                  3) organization - ( I didnt create a separate table for organization )

           B) CF : ORG_USER
                 1) organization - Primary Key
                 2) email_id

                 Here, my intention is to get users belong to an organization.
                 Here, I can make the organization in the user table as secondary index, but heard that, this may hit the performance.
                 Could you please clarify me which is the better approach?