On Fri, Jul 22, 2011 at 12:05 AM, Eldad Yamin <elda...@gmail.com> wrote:
> In order order to split the nodes. > SimpleGeo have max 1,000 recods (i.e places) on each node in the tree, if > the number is >1,000 they split the node. > In order to avoid that more then 1 process will edit/split the node - > transaction is needed. > You don't need a transaction, you just need consensus and/or idempotence. In this case both can be achieved fairly easily. Mike > On Jul 22, 2011 1:01 AM, "aaron morton" <aa...@thelastpickle.com> wrote: > >> But how will you be able to maintain it while it evolves and new data is > added without transactions? > > > > What is the situation you think you need transactions for ? > > > > Cheers > > > > ----------------- > > Aaron Morton > > Freelance Cassandra Developer > > @aaronmorton > > http://www.thelastpickle.com > > > > On 22 Jul 2011, at 00:06, Eldad Yamin wrote: > > > >> 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 > >> > >> * 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. > >> > >> > > >
