Ancestry is a gem that allows the records of a Ruby on Rails ActiveRecord model
to be organised as a tree structure (or hierarchy). It employs the materialised
path pattern and exposes all the standard tree structure relations (ancestors,
parent, root, children, siblings, descendants), allowing all of them to be
fetched in a single SQL query. Additional features include STI support, scopes,
depth caching, depth constraints, easy migration from older gems, integrity
checking, integrity restoration, arrangement of (sub)trees into hashes, and
various strategies for dealing with orphaned records.

• Pavel Skrylev
• Andrey Cherepanov

• gem-ancestry
• gem-ancestry-devel
• gem-ancestry-doc