Hi Tinus, > On 12 Dec 2013, at 6:59 pm, Tinus Sky <tinus...@gmail.com> wrote: > > My service does have users who can add a message to a list. The list of > message is sorted by date and displayed. When a user changes the message the > date is changed and the message moves to the top of the list. > > A possible solution is to remove row and insert it again, but i suspect this > might be not the best solution. Is there a alternative solution?
Just insert a new "version" of the message, with a version field into the table/columnfamily. When outputting query results to the user, filter/hide older versions. And bam you have a new feature in your web site called "show old versions" or "show previous edits". > My second question is regarding the number of tables/column families in a > keyspace. > > I can create a table which contains all messages from all users. But i can > also create one table for every user which has a name like: > messages_[userid], where [userid] is the id of the user. Or i can shard: > messages_a (contains messages from user where name starts with a), messages_b > (contains messages from user where name starts with b) > > My users count is around 100.000. And the messages per user are approx around > 20.000. > > What would be the choice: put everything in 1 big table or go with the many > small tables option. I'm pretty sure you don't want to put 100,000 tables in a Cassandra key space. Go with one. Regards, Jacob
