In order to facilitate efficient storage and extraction of data, a system may represent a compound relationship in a graph stored in a graph database. In particular, the system (or a user) may define the compound relationship based on two or more predicates associated with two or more edges between two or more nodes in the graph. Then, the system may generate, in the graph, a hub node that corresponds to the compound relationship and that has an identifier that is hidden from users of the graph so that the identifier of the hub node is not visible external to the graph database. Moreover, the identifier of the hub node may be specified in a query using the two or more predicates, thereby allowing data associated with the compound relationship to be readily identified, modified and/or extracted.