Also, the Nested Sets seem to solve problems I don't have -- such as
finding all descendants of a given node.
you can also check different way.
i described it here:
http://www.depesz.com/various/various-sqltrees-implementation.php
it is in polish, but it's full of examples and should be readable even for somebody with 0 knowledge of polish.
basically - this is extension of adjacency list which allows all kinds of access without recursive queries.
in case you'd have questions with this - please do not hesitate to ask,
best regards,
depesz
