I think this is a typical paradigm that's suit for many-to-many relationship
Jeff Zhang On Sun, Dec 27, 2009 at 12:52 AM, August Zajonc <augu...@augustz.com> wrote: > Just getting up to speed with Cassandra and the terminology and > concepts. Lots of fun. Apologies for a beginner question. > > Focusing on how the data will be used is very helpful in coming up > with a model. > > I have a question about a design pattern I expect is relatively > common. It's the tag pattern (or sets or inverted index...) > > Item A > - Tag A > - Tag B > - Tag C > > Tag A > - Item A > - Item B > - Item C > > I want fast access using the item as a key and fast access when using > the tag as a key (inverted index). This let's met answer the > questions, what tags have been applied to this item, and what items > belong to this tag, both very quickly. > > Looking at the data model a simple solution is two column families, > one containing items as the row-key with tags as columns, and a second > with tags as the row-key with items as columns. This gives me fast > access at the cost of 2x the writes (cheap) and storage (also cheap). > So not bad. > > Curious what the standard pattern is here. > > One other issue is consistency. Since my writes are idempotent > consistency could be maintained with a writelog or similar replayed on > recovery. It feels like this will have been done enough someone will > have some good pointers. > > Many cheers, > > - August >
