On Wed, Oct 26, 2011 at 9:35 PM, Ben Gambley <ben.gamb...@intoscience.com>wrote:
> > Hi Everyone > > I have a question with regards read performance and schema design if > someone could help please. > > > Our requirement is to store per user, many unique results (which is > basically an attempt at some questions ..) so I had thought of having the > userid as the row key and the result id as columns. > > The keys for the result ids are maintained in a separate location so are > known without having to perform any additional lookups. > > My concern is that over time reading a single result would incur the > overhead of reading the entire row from disk so gradually slow things down. > > > So I was considering if changing the row key to *userid + result id* would > be a better solution ? > > Do you regularly need to read all of the results for a given userid? If not, go with the user_id + result_id approach. It will be more efficient for single-result lookups. -- Tyler Hobbs DataStax <http://datastax.com/>
