Storage device for graph data

A storage device includes a controller configured to receive a pre-processing instruction command from an external device, a non-volatile memory configured to store an original graph data, and a buffer memory connected to the controller and the non-volatile memory, wherein the controller is configured to load the original graph data from the non-volatile memory, generate pre-processing graph data by classifying the original graph data depending on vector similarity in response to the pre-processing instruction command, generate metadata on the basis of the pre-processing graph data, and provide the pre-processing graph data and the metadata to the non-volatile memory, the non-volatile memory is configured to store the pre-processing graph data and the metadata in a data block, and the buffer memory is configured to buffer the original graph data, the pre-processing graph data, and the metadata.