1. A method comprising: representing a data model as a graph, the graph stored at a first memory location, and the graph including an assertion as a reified n-ary relation represented as a node in the graph with edges linking to concepts participating in the relation; ingesting the graph, including traversing the graph and flattening one or more node paths and storing the paths, the traversal comprising: following all paths from a current concept to a root concept; following all paths from a category of the current concept to a root category; following a neighborhood of the current concept to an adjacent concept, wherein neighbor data demonstrates a non-hierarchical relationship of the current concept to a neighboring concept; and converting the ingested graph into a set of flat document structures supported by information ranking and retrieval framework, and storing the document structure at a second memory location.