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From List <>
Subject Re: Arbitrary nested tree hierarchy data model
Date Fri, 27 Mar 2015 13:31:58 GMT
On 3/26/15 10:15 PM, Robert Wille wrote:
> I have a cluster which stores tree structures. I keep several hundred unrelated trees.
The largest has about 180 million nodes, and the smallest has 1 node. The largest fanout is
almost 400K. Depth is arbitrary, but in practice is probably less than 10. I am able to page
through children and siblings. It works really well.
> Doesn’t sound like its exactly like what you’re looking for, but if you want any
pointers on how I went about implementing mine, I’d be happy to share.
> On Mar 26, 2015, at 3:05 PM, List <> wrote:
>> Not sure if this is the right place to ask, but we are trying to model a user-generated
tree hierarchy in which they create child objects of a root node, and can create an arbitrary
number of children (and children of children, and on and on).  So far we have looked at storing
each tree structure as a single document in JSON format and reading/writing it out in it's
entirety, doing materialized paths where we store the root id with every child and the tree
structure above the child as a map, and some form of an adjacency list (which does not appear
to be very viable as looking up the entire tree would be ridiculous).
>> The hope is to end up with a data model that allows us to display the entire tree
quickly, as well as see the entire path to a leaf when selecting that leaf.  If anyone has
some suggestions/experience on how to model such a tree heirarchy we would greatly appreciate
your input.


This certainly sounds like a step in the right direction so yes please 
do share!  Thank you.

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