On Nov 19, 12:23 pm, Marnen Laibow-Koser <[email protected]> wrote:
> > Hell no! acts_as_tree should be avoided at all costs. The adjacency > list model that it uses is simple, naïve, and inefficient: each level of > the tree requires a separate query (unless you're using Oracle, which > has a proprietary extension to its SQL that fixes this). > > What you want instead is a *nested set* or *nested interval* structure > (do a Web search for articles on how these work). These allow retrieval > of an entire tree, to arbitrary depth, with a single query. Rails > plugins exist for both. acts_as_nested_interval was buggy last time I > used it, but has probably been fixed by now. awesome_nested_set lives > up to its name. > Although nested sets make inserts very expensive. Like most data modelling questions, the sort of access patterns that will be used - while acts as tree makes getting a whole subtree expensive, if you never need to do that in your app, who cares? Fred > > > > -- > > Cheers, > > Bala > > RoR Developer Now Available for Hire > > The fact that you're recommending acts_as_tree means that people ought > to think twice about hiring you... > > Best, > -- > Marnen Laibow-Koserhttp://www.marnen.org > [email protected] > > Sent from my iPhone > > -- > Posted viahttp://www.ruby-forum.com/. -- You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" 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/rubyonrails-talk?hl=en.
