On 28/11/2011, at 5:52 PM, Dmytrii Nagirniak wrote:

> I wonder how you guys work with the persistent ordered graph structures.
> 
> What I need to be able to do is to propagate all the changes from a node to 
> all its child nodes recursively.
> 
> A node is basically a permission (loaded with the information, such as 
> subject, user, company etc) that is propagated through to the other nodes.

Is "propagating changes to all child node recursively" a strategy to improve 
query performance?

If so, you might look at an ActiveRecord extension such as my "Arboreal" 
(shameless plug), or DHH's "acts_as_nested_set", to allow efficient queries on 
a tree structure.

https://github.com/mdub/arboreal
https://github.com/rails/acts_as_nested_set

I did presentation last year, that included an example of using Arboreal to 
query down a hierarchy (e.g. of roles or groups) while joining with another 
table (e.g. permissions).  See page 10 of:

http://www.slideshare.net/mdubya/one-project-3-gems

-- 
cheers, 
Mike Williams

-- 
You received this message because you are subscribed to the Google Groups "Ruby 
or Rails Oceania" group.
To post to this group, send email to [email protected].
To unsubscribe from this group, send email to 
[email protected].
For more options, visit this group at 
http://groups.google.com/group/rails-oceania?hl=en.

Reply via email to