Peter, Do you think 0-padding the entries would be more efficient than just implementing your own comparator?
On Wed, Mar 24, 2010 at 10:57 PM, Peter Chang <pete...@gmail.com> wrote: > If there's not much overhead, I recommend client side as well. > Otherwise, you can only sort on column. Therefore, you could create some > sort of inverted index based on the message count. > User 1 sent 50 messages. > User 2 sent 10 messages. > User 3 sent 25 messages. > Then store a separate index that looks like: > -> 50-User-1-Key > -> 25-User-2-Key > -> 10-User-2-Key > You'd also have to 0-pad your count so that numbers are correctly compared > (12 is less than 110) since you'll have to use some lexical-based sorting. > > > On Wed, Mar 24, 2010 at 1:36 PM, Erez Efrati <ere...@gmail.com> wrote: >> >> Hi, >> I can't figure out how to use model the following using column family and >> the way the columns are sorted (by their name). >> Lets say I have a list of users and for each user I wish to display a list >> of all the friends he has ordered by the number of messages they sent him so >> far (desc from most to least). >> I can't see how this is going to work since the columns sorting is always >> by the name of the column and not its value. I thought of having a row for >> each user and the columns will be the friends that email him. But the column >> name needs to be the number of messages to be sorted and the value will be >> the friend's user ID. But then, when a friend is sending a message to >> another user how do I increment his count of message he sent so far to that >> user? >> How can I model this with Cassandra? Is it possible? >> Thanks in advance, >> Erez Efrati > -- Maybe she awoke to see the roommate's boyfriend swinging from the chandelier wearing a boar's head. Something which you, I, and everyone else would call "Tuesday", of course.
