I think you need another CF as index. user_itemid -> timestamped column_name
Otherwise you can't guess what's the timestamp to use in the column name. Anyway I would prefer storing the item-ids as column names in the main column family and having a second CF for the order-by-date query only with the pair timestamp_itemid. That way you can add later other query strategies without messing with how you store the item information. Maybe you can solve it with a secondary index by timestamp too. Guille On Thu, Aug 23, 2012 at 7:26 AM, Roshni Rajagopal < roshni.rajago...@wal-mart.com> wrote: > Hi, > > Need some help on a data modelling question. We're using Hector & Datastax > Enterprise 2.1. > > > I want to associate a list of items for a user. It should be sorted on the > time added. And items can be updated (quantity of the item can be changed), > and items can be deleted. > I can model it like this so that its denormalized and I get all my > information in one go from one row, sorted by time added. I can use > composite columns. > > Row key: User Id > Column Name: TimeUUID:item ID: Item Name: Item Description: Item Price: > Item Qty > Column Value : Null > > Now, how do I handle manipulations > > 1. Add new item :Easy , just a new column > 2. Add exiting item or modify qty: I want to get to the correct column > to update . Can I search by second column in the composite column (equals > condition) & update the column name itself to reflect new TimeUUID and qty? > Or would it be better to just add it as a new column and always use the > latest column for an item in the application code and delete duplicates in > the background. > 3. Delete item: Can I search by second column in the composite column to > find the correct column to delete? > > I was trying to find hector examples where we search for second column in > a composite column, but I couldn't find any good one. Im not sure if its > possible.…if you have any do have any example please share. > > Regards, > Roshni > > > This email and any files transmitted with it are confidential and intended > solely for the individual or entity to whom they are addressed. If you have > received this email in error destroy it immediately. *** Walmart > Confidential *** >
