Joe Celko’s Trees and Hierarchies in SQL for Smarties: A book devoted to nothing but representing hierachies and trees in relational (SQL) databases. Am I a dork because I want it?
In this book, Celko illustrates several major approaches to representing trees and hierarchies and related topics that should be of interest to the working database programmer. These topics include hierarchical encoding schemes, graphs, IMS, binary trees, and more.
I paged through it at the bookstore. It’s heavy on the nested set theory, rather than parent-child.
Nah, you're not a dork. I actually could have used this the other day for an app I'm writing at work.
Read this article from SitePoint:
http://www.sitepoint.com/article/hierarchical-data-database
It compares the traditional parent-child theory against nested-set theory. The former is optimized for writes, the latter for reads.
