There are some more tricks you can do using postgres' arrays to efficiently query the data: http://monkeyandcrow.com/blog/hierarchies_with_rails/ http://monkeya

There are some more tricks you can do using postgres' arrays to efficiently query the data: http://monkeyandcrow.com/blog/hierarchies_with_rails/ http://monkeyandcrow.com/blog/hierarchies_with_rails/ Namely using the && operator let's you make use of indices on the materialized paths. We've been using it in production for years to great effect.