Thanks Aaron, this was a big help!

Sent from Mailbox for iPhone

On Thu, Feb 21, 2013 at 9:27 AM, aaron morton <> wrote:

If you have a limited / known number (say < 30)  of types, I would create a CF for each of them.

If the number of types is unknown or very large I would have one CF with the row key you described. 

Generally I avoid data models that require new CF's as the data grows. Additionally having different CF's allows you to use different cache settings, compactions settings and even storage mediums. 

Aaron Morton
Freelance Cassandra Developer
New Zealand


On 21/02/2013, at 7:43 AM, Adam Venturella <> wrote:

My data needs only require me to store JSON, and I can handle this in 1 column family by prefixing row keys with a type, for example:


Where comments: represents the prefix and {message_id} represents some row key to a message object in the same column family.

In this case comments:{message_id} would be a wide row using comment creation time and descending clustering order to sort the messages as they are added.

My question is, would I be better off splitting comments into their own Column Family or is storing them in with the Messages Column Family sufficient, they are all messages after all.

Or do Column Families really just provide a nice organizational front for data. I'm just storing JSON.