Hierarchical Data Storage Technique Comparisons

http://en.wikipedia.org/wiki/Hierarchical_database_model

http://codeidol.com/sql/artofsql/Variations-in-Tactics/Representing-Trees-in-an-SQL-Database/

(detailed sql) (adjacency lists and nested sets) Managing Hierarchical Data in MySQL: http://mikehillyer.com/articles/managing-hierarchical-data-in-mysql/

Efficient tree model implementations for Django (Adjacency List, Materialized Path and Nested Sets): http://django-treebeard.googlecode.com/svn/docs/index.html

(big list of links) Hierarchical data in RDBMSs: http://troels.arvin.dk/db/rdbms/links/#hierarchical

(adjacency list, nested set, nosql) Modeling a Tree in a Document Database: http://seancribbs.com/tech/2009/09/28/modeling-a-tree-in-a-document-database/

(low tech) Four ways to work with hierarchical data: http://evolt.org/node/4047/

Options for Storing Hierarchical Data in a Relational Database: http://stackoverflow.com/questions/4048151/what-are-the-options-for-storing-hierarchical-data-in-a-relational-database

Adjacency list vs. nested sets: http://explainextended.com/2009/09/29/adjacency-list-vs-nested-sets-mysql/

Some answers to some common questions about SQL trees and hierarchies (Joe Celko): http://www.ibase.ru/devinfo/DBMSTrees/sqltrees.html

Storing Hierarchical Data in a Database: http://blogs.sitepoint.com/hierarchical-data-database/

Trees in SQL: Nested Sets and Materialized Path: https://communities.bmc.com/communities/docs/DOC-9902

how to store and navigate hierarchies: http://stackoverflow.com/questions/38801/sql-how-to-store-and-navigate-hierarchies

(nested sets) Algorithms for Management of Nested Set Data Model: http://forums.oracle.com/forums/thread.jspa?threadID=1659509

A Flexible Tree Structure: http://www.tonymarston.net/php-mysql/tree-structure.html

http://www.sitepoint.com/hierarchical-data-database/

Trees in SQL: Nested Sets and Materialized Path: https://communities.bmc.com/communities/docs/DOC-9902

most efficient/elegant way to parse a flat table into a tree?: http://stackoverflow.com/questions/192220/what-is-the-most-efficient-elegant-way-to-parse-a-flat-table-into-a-tree/192462#192462

http://explainextended.com/2009/09/29/adjacency-list-vs-nested-sets-mysql/

http://explainextended.com/2009/09/24/adjacency-list-vs-nested-sets-postgresql/

http://www.artfulsoftware.com/mysqlbook/sampler/mysqled1ch20.html

http://vadimtropashko.wordpress.com/2008/08/09/one-more-nested-intervals-vs-adjacency-list-comparison/

http://web.archive.org/web/20081121131640/http://www.dbmsmag.com/9603d06.html

http://bytes.com/topic/postgresql/answers/174528-making-tree-millions-millions-dynamic-nodes