1. A computing system comprising: a control unit configured to: detect an upcoming event for interacting with a focal person for the upcoming event; extract an invitee's identification for the upcoming event, aggregate an invitee's information associated with the invitee's identification; build a social graph as an enhanced graph or with an extension graph based on the invitee's information for adding an invitee associated with the invitee's identification; and a storage unit, coupled to the control unit, configured to store the social graph.