search for: descendend

...t adds two integer fields, a "left counter" and "right counter", to each row. By updating these in the right way as rows are inserted and deleted in the tree, you can use them to reduce a lot of common tree operations -- like getting the path to a node or finding all the descendends of a node -- to a single query. I used this in the original PHP implementation of my app. I''m sure it can be done easily in Rails, but I''m not comfortable yet doing direct SQL munging on ActiveRecord, so I''d appreciate any tips or pointers to existing code. --Jen...