Lets start with something quick and simple, all standard Column Families…
Visitant CF key: id column name: property name column value: property value Visitant Sessions CF key: visitant id column name: session id column value: none Session CF key: session_id column_name: property value column_value: property value key: session_id/requests column_name: request_id column_value: none key: session_id/events column_name: event_id column_value: none Requests CF key: request_id column_name: property name column_value: property value Event CF key: event_id column_name: property name column_value: property value Notes: * assuming the Visitant CF is slowing changing i kept it in it's own cf. * using compound keys to keep information related to sessions in the same CF. These could be diff CF's,or in the Request or Event CF. * the best model is the one that allows you to do your reads by getting one or a few rows from a single cf. * you could collapse the Request and Event CF's into one. If the event and request data is immutable (or there is no issues with concurrent modifications) I would recommend this… Request / Event CF: key: session_id/events or session_id/requests column_name: event_id or session_id column_value: data Start with the simple model and then make changes to better handle your read queries. Have fun :) ----------------- Aaron Morton Freelance Cassandra Developer @aaronmorton http://www.thelastpickle.com On 22/08/2011, at 11:13 PM, Helder Oliveira wrote: > Hello all, > > i have a SQL structure like this: > > Visitant ( has several properties ) > Visitant has many Sessions > Sessions ( has several properties ) > Sessions has many Requests ( has several properties ) > Sessions has many Events ( has several properties ) > > > i have read a lot and still confused how to put this on cassandra, can > someone give me a idea ?
