Hi everyone! This may be more a database question than a Rails question, but here goes. I have a few questions about implementing tree structures in my Rails app. It looks like I'll run into performance issues any way I slice it, so I'd love to kick around options with people who have actually done this before.
The situation is this: I have an application where users can create items. Each item has a record in the items table. Although users cannot edit items created by others, they *can* create a variant of another user's item (kind of like forks on GitHub) and edit that. And variants can spawn their own variants. This means that there is a tree structure of items and their variants: Item 1 (by Joe) |- Item 1 variant A (by Bob) | '- Item 1 variant A1 (by Alice) '- Item 1 variant B (by Mary) Item 2 (by Alice) '- Item 2 variant (also by Alice) If the app takes off, there could potentially be thousands of nodes, and I can expect both node creation and tree retrieval to be quite frequent. Therefore, I am trying to find a structure where it is not too expensive to show an item and all its descendants, but where it's also not too expensive to create a new item. Right now, I'm using acts_as_tree, which makes it very cheap to add a new node to the tree, but appears to also make it expensive to get a list of an item's descendants. I'm considering switching to a nested- set-based approach (probably BetterNestedSet at http://opensource.symetrie.com/api/better_nested_set/ ), but while this would make tree retrieval extremely cheap, I am worried about having to change all records in the database each time a node is added. Does anyone have any thoughts on which way to go here? It looks a bit like I'm damned if I do and damned if I don't. Thanks, -- Marnen Laibow-Koser [email protected] http://www.marnen.org --~--~---------~--~----~------------~-------~--~----~ 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 -~----------~----~----~----~------~----~------~--~---
