You'll need to use two CF's to achieve that. Denormalising to support a workload like that is not a terrible idea.
Depending on how big the 7 days hot set is you may get benefit from using a large row cache with one CF. Maybe worth doing some testing. CHeers ----------------- Aaron Morton Freelance Cassandra Developer New Zealand @aaronmorton http://www.thelastpickle.com On 19/02/2013, at 3:26 PM, Kanwar Sangha <[email protected]> wrote: > Thanks. I will look into the details. > > One issue I see is that if I have only one column family which needs only the > last 7 days data to be on SSD and the rest to be on the HDD, how will that > work. > > From: Michael Kjellman [mailto:[email protected]] > Sent: 18 February 2013 20:08 > To: [email protected] > Subject: Re: Cassandra backup > > There is this: > > http://www.datastax.com/dev/blog/whats-new-in-cassandra-1-1-flexible-data-file-placement > > But you'll need to design your data model around the fact that this is only > as granular as 1 column family > > Best, > michael > > From: Kanwar Sangha <[email protected]> > Reply-To: "[email protected]" <[email protected]> > Date: Monday, February 18, 2013 6:06 PM > To: "[email protected]" <[email protected]> > Subject: Cassandra backup > > Hi – We have a req to store around 90 days of data per user. Last 7 days of > data is going to be accessed frequently. Is there a way we can have the > recent data (7 days) in SSD and the rest of the data in the > HDD ? Do we take a snapshot every 7 days and use a separate ‘archive’ cluster > to serve the old data and a ‘active’ cluster to serve recent data ? > > Any links/thoughts would be helpful. > > Thanks, > Kanwar
