Joe Celko's Trees and Hierarchies in SQL for Smarties

Too theoretical. Juggled a few examples, shifting from one to the next when convenient for the narrative rather than when the topic was sufficiently covered. Not enough figures and graphs to illustrate abstractions. I would have preferred a top-down description and a single complex model I could reverse-engineer than a dozen bottom-up examples I'm supposed to mentally integrate into a cohesive understanding. Would probably be a fine textbook for a college-level course where you had an instructor to provide the top-down and the objective of building a working model by the end of the term, but a poor choice for autodidacts interested in the particulars of schemas and algorithms for manipulating them.