1. A graph database, comprising: a database interface that connects the graph database to a communication network; and a data storage medium comprising a plurality of data elements stored therein, the plurality of data elements including an attribute tree having a plurality of nodes and at least one relationship defined between the plurality of nodes, wherein the plurality of nodes represent attributes of resources in a contact center and the at least one relationship enables a work assignment engine to traverse the nodes of the attribute tree when making a work assignment decision, wherein every data element in the graph database is directly linked to every one of its adjacent data elements.