Either you do that or you could think about using a secondary index on the fb user name in your primary cf.
See http://www.datastax.com/docs/1.0/ddl/indexes Cheers Am 11.03.2012 um 09:51 schrieb Tamar Fraenkel <ta...@tok-media.com>: Hi! I need some advise: I have user CF, which has a UUID key which is my internal user id. One of the column is facebook_id of the user (if exist). I need to have the reverse mapping from facebook_id to my UUID. My intention is to add a CF for the mapping from Facebook Id to my id: user_by_fbid = { // key is fb Id, column name is our User Id, value is empty 100003101876963: { f94f6b20-161a-4f7e-995f-0466c62a1b6b : "" } } Does this makes sense. This CF will be used whenever a user log in through Facebook to retrieve the internal id. Thanks *Tamar Fraenkel * Senior Software Engineer, TOK Media <tokLogo.png> ta...@tok-media.com Tel: +972 2 6409736 Mob: +972 54 8356490 Fax: +972 2 5612956