1. A relational graph database system that manages a database containing graph data including node data connected through links, the relational graph database system comprising: a node generation unit that generates node data corresponding to an operation in a terminal device connected to a computer network; a partial graph generation unit that generates partial graph data including a plurality of node data connected through links; and a graph generation unit that synthesizes a plurality of partial graph data to generate graph data and stores the generated graph data in the database, wherein the node generation unit can generate a plurality of types of node data corresponding to a plurality of types of operations conducted in the terminal device, when a plurality of operations conducted in an identical terminal device have a prescribed relationship, the partial graph generation unit connects a plurality of node data corresponding to the plurality of operations through links to generate partial graph data, and the graph generation unit conducts graph synthesis of a plurality of partial graph data containing common node data in the common node data to generate graph data, or conducts graph synthesis of graph data and partial graph data that contain common node data in the common node data to generate new graph data.