1. A device comprising: means for manipulating a given object, the given object comprising a mapping of at least a portion of graph data comprising one or more nodes and one or more edges connecting the one or more nodes as table data; means for accessing a graph repository storing the graph data; means for specifying, from among nodes in the graph data that are related to the given object, at least one shared node that is also related to one or more other objects; and means for reflecting the manipulation of the given object in the graph data while preserving relationships of the specified shared node with the one or more other objects; wherein the mapping of the given object is defined by at least one graph matching pattern, each graph matching pattern comprising a plurality of different node variables including a representative node variable and a unique node variable, the representative node variable being subject to a first constraint condition and the unique node variable being subject to a second constraint condition; wherein the first constraint condition specifies that there is at most one node in the graph data that matches a representative node variable for a given one of the graph matching patterns, the at most one node matching the representative node variable for the given graph matching pattern not matching one or more other node variables in another graph matching pattern unless the other graph matching pattern has an inheritance relationship with the given graph matching pattern; wherein the second constraint condition specifies that a node matching a unique node variable in the graph data for the given graph matching pattern uniquely corresponds to the representative node variable in the given graph matching pattern; and wherein object data corresponding to the given object comprises a first portion matching the representative node variable and the unique node variable that is a homomorphism of the graph data and a second portion including the specified shared node that is not a homomorphism of the graph data.