Abstract: Presented here are systems and methods to efficiently provide an answer to a query regarding an event and a third-party not expressly involved with the event. To efficiently provide the answer, mutually referential data structures can be created, each data structure representing a different aspect of the event. The mutually referential data structures can include references to each other. One or more of the mutually referential data structures can be recorded in a block chain ledger. For example, one data structure can represent a time ordered list of events, another data structure can represent the third-party, event categories, and the events associated with the third-party in the event categories, while another data structure can define the current state and represent most recent events containing an event category. But representing multiple aspects of the transaction, the efficiency of the lookup can be increased by up to eight orders of magnitude.

Abstract: A method and data structures for obtaining, distributing, managing, and utilizing information, including online content and user biographical information, in an online networking system are presented. Profile data pointers that point to profile data structures and item data pointers that point to item data structures are employed to access users' views and media content in a manner that allows for viral copying of content throughout the system yet permits the system and content owners to maintain control over the content. Users' biographical information is developed based in part on users' behavior in the networking system, and is collected and aggregated in the respective data structures to support targeted advertising based on the data, and protection of users' personally identifying information.