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From Tyler Hobbs <ty...@datastax.com>
Subject Re: Datastructure time tracking
Date Fri, 18 Nov 2011 04:51:14 GMT
On Thu, Nov 17, 2011 at 2:36 PM, RobinUs2 <robin@us2.nl> wrote:

> We're currently developing a system with a time tracking part. We need to
> store following details:
> - user
> - time (in minutes)
> - description
> - billable
> - project
> - task ID
>
> What would be a proper data structure for this in Cassandra?


 How do you need to be able to query the data? Specific details matter.
For example, do you just need to know what happened for a specific user
during a given time period?  Or do you need to know what happened across
all users during a given time period?  All users of a given project?

These details matter because in Cassandra you tend to have one column
family per type of query that you need to be able to answer efficiently
(i.e. in real time).  Ad-hoc queries aren't efficient on large, distributed
data sets like you tend to use Cassandra for; you need to know what your
reads will look like to know how to model your data.

-- 
Tyler Hobbs
DataStax <http://datastax.com/>

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