Gary, Did you see this larticle linked from the Cassandra wiki? http://about.digg.com/node/564
See http://wiki.apache.org/cassandra/ArticlesAndPresentations for more examples like the above. In general, you structure your data according to how it will be queried. This can lead to duplication, but that is one of the trade-offs for performance and scale. Digg folks - the "Looking to the Future with Cassandra" linked on the wiki is no longer available. I found that article quite helpful originally. Is there a chance this could be re-posted? Cheers, -Nate On Fri, Mar 19, 2010 at 12:16 PM, Gary <daxia...@gmail.com> wrote: > I am a newbie to bigtable like model and have a question as follows. Take > Digg as an example, I want to find a list users who dug a URL and also want > to find a list of URLs a user dug. How should the data model look like for > the queries to be efficient? If I use the username and the URL for two rows, > when a user digs a URL, I will have to update two rows so I need a > transaction to keep data consistent. > Any thoughts? > Thanks, > Gary