Aaron, Nested set is exactly what I had in mind. But how will you be able to maintain it while it evolves and new data is added without transactions?
Thanks! On Thu, Jul 21, 2011 at 1:44 AM, aaron morton <aa...@thelastpickle.com>wrote: > Just throwing out a (half baked) idea, perhaps the Nested Set Model of > trees would work http://en.wikipedia.org/wiki/Nested_set_model > > <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. > > >
