A technique for representing the structure of hierarchically-organized data in a non-hierarchical data structure, such as a relation. The hierarchically-organized data is represented as a tree, and each node in the tree is assigned a position identifier that represents both the depth level of the node...http://www.google.fr/patents/US7421445?utm_source=gb-gplus-shareBrevet US7421445 - System and method for relational representation of hierarchical data
System and method for relational representation of hierarchical data
