There is no facility to do custom reconciliation for a column. An append style operation would run into many of the same problems as the Counter type, e.g. not every node may get an append and there is a chance for lost appends unless you go to all the trouble Counter's do.
I would go with using a row for the user and columns for each item. Then you can have fast no look writes. What problems are you seeing with the reads ? Cheers ----------------- Aaron Morton Freelance Cassandra Developer @aaronmorton http://www.thelastpickle.com On 29 Jun 2011, at 04:20, Yang wrote: > for example, if I have an application that needs to read off a user browsing > history, and I model the user ID as the key, > and the history data within the row. with current approach, I could model > each visit as a column, > the possible issue is that *possibly* (I'm still doing a lot of profiling on > this to verify) that a lot of time is spent on serialization into the message > and out of the > message, plus I do not need the full features provided by the column : for > example I do not need a timestamp on each visit, etc, > so it might be faster to put the entire history in a blob, and each visit > only takes up a few bytes in the blob, and > my code manipulates the blob. > > problem is, I still need to avoid the read-before-write, so I send only the > latest visit, and let cassandra do the reconcile, which appends the > visit to the blob, so this needs custom reconcile behavior. > > is there a way to incorporate such custom reconcile under current code > framework? (I see custom sorting, but no custom reconcile) > > thanks > yang
