Thinking out loud and I think a bit towards playOrm's model though you don’t' 
need to use playroom for this.

1. I would probably have a User with the requests either embedded in or the 
Foreign keys to the requests…either is fine as long as you get the user get ALL 
FK's and make one request to get the requests for that user

2. I would create rows for index and index each month of data OR maybe index 
each day of data(depends on your system).  Then, I can just query into the 
index for that one month.  With playOrm S-SQL, this is a simple PARTITIONS 
r(:thismonthParititonId) SELECT r FROM Request r where r.date > :date OR you 
just do a column range query doing the same thing into your index.  The index 
is basically the wide row pattern ;) with composite keys of <date>.<rowkey of 
request>

Later,
Dean

From: Marcelo Elias Del Valle <mvall...@gmail.com<mailto:mvall...@gmail.com>>
Reply-To: "user@cassandra.apache.org<mailto:user@cassandra.apache.org>" 
<user@cassandra.apache.org<mailto:user@cassandra.apache.org>>
Date: Wednesday, September 19, 2012 1:02 PM
To: "user@cassandra.apache.org<mailto:user@cassandra.apache.org>" 
<user@cassandra.apache.org<mailto:user@cassandra.apache.org>>
Subject: Correct model

I am new to Cassandra and NoSQL at all.
I built my first model and any comments would be of great help. I am describing 
my thoughts bellow.

It's a very simple model. I will need to store several users and, for each 
user, I will need to store several requests. It request has it's insertion 
time. As the query comes first, here are the only queries I will need to run 
against this model:
- Select all the requests for an user
- Select all the users which has new requests, since date D

I created the following model: an UserCF, whose key is a userID generated by 
TimeUUID, and a RequestCF, whose key is composite: UserUUID + timestamp. For 
each user, I will store basic data and, for each request, I will insert a lot 
of columns.

My questions:
- Is the strategy of using a composite key good for this case? I thought in 
other solutions, but this one seemed to be the best. Another solution would be 
have a non-composite key of type UUID for the requests, and have another CF to 
relate user and request.
- To perform the second query, instead of selecting if each user has a request 
inserted after date D, I thought in storing the last request insertion date 
into the userCF, everytime I have a new insert for the user. It would be a data 
replication, but I would have no read-before-write and I am guessing the second 
query would perform faster.

Any thoughts?

--
Marcelo Elias Del Valle
http://mvalle.com - @mvallebr

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