Just throwing out a (half baked) idea, perhaps the Nested Set Model of trees would work http://en.wikipedia.org/wiki/Nested_set_model
* Ever row would represent a set with a left and right encoded into the key * Members are inserted as columns into *every* set / row they are a member. So we are de-normalising and trading space for time. * May need to maintain a custom secondary index of the materialised sets. e.g. slice a row to get the first column >= the left value you are interested in, that is the key for the set. I've not thought it through much further than that, a lot would depend on your data. The top sets may get very big, . Cheers ----------------- Aaron Morton Freelance Cassandra Developer @aaronmorton http://www.thelastpickle.com On 21 Jul 2011, at 08:33, Jeffrey Kesselman wrote: > Im not sure if I have an answer for you, anyway, but I'm curious.... > > A b-tree and a binary tree are not the same thing. A binary tree is a basic > fundamental data structure, A b-tree is an approach to storing and indexing > data on disc for a database. > > Which do you mean? > > On Wed, Jul 20, 2011 at 4:30 PM, Eldad Yamin <elda...@gmail.com> wrote: > Hello, > Is there any good way of storing a binary-tree in Cassandra? > I wonder if someone already implement something like that and how > accomplished that without transaction supports (while the tree keep evolving)? > > I'm asking that becouse I want to save geospatial-data, and SimpleGeo did it > using b-tree: > http://www.readwriteweb.com/cloud/2011/02/video-simplegeo-cassandra.php > > Thanks! > > > > -- > It's always darkest just before you are eaten by a grue.
