I have an existing system in postgres that I would like to move to cassandra.  The system is for building registration forms for conferences.

For example, you might want to build a registration form (or survey) that has a bunch of questions on it.  An overview of this system I whiteboarded here: http://paste2.org/JeHP1tV0

What I'm trying to figure out is how this data should be structured in a de-normalized way?

Basic queries would be:
1. Give me all surveys for an account
2. Give me all questions for a survey
3. Give me all responses for a survey
4. Give me all responses for a specific question
5. Compare responses for question "What is your favorite color" with people who answered question "What is your gender".  i.e  a crosstab of males/females and the colors they like.
6. Give me a time series of how many people responded to a question per hour

The reason I would like to get it on cassandra is because currently at peak times this is an extremely write heavy application since people are registering for a conference that launched or filling out a new survey, so everyone comes in all at once.

Also, if anyone is in the bay area and wants to discuss cassandra data modeling over some beers, let me know!

Thanks,
John