Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for referenced access control lists. In one aspect, a method includes accessing an object hierarchy for a plurality of objects, each object being representative of one of a storage location or a file. The object hierarchy includes for each object, a respective node, for each object that is a parent object having a child object, a directed edge connecting the node representing the parent object. In addition, for each object, including metadata that includes an access control list identifier that identifies an access control list for the object and that is owned by an access control list root object. The method including receiving updates to an access control list for particular objects, generating a new access control list, and storing the new access control list identifier in metadata for each object that descends from the particular object.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for referenced access control lists. In one aspect, a method includes accessing an object hierarchy for a plurality of objects, each object being representative of one of a storage location or a file. The object hierarchy includes for each object, a respective node, for each object that is a parent object having a child object, a directed edge connecting the node representing the parent object. In addition, for each object, including metadata that includes an access control list identifier that identifies an access control list for the object and that is owned by an access control list root object. The method including receiving updates to an access control list for particular objects, generating a new access control list, and storing the new access control list identifier in metadata for each object that descends from the particular object.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for referenced access control lists. In one aspect, a method includes accessing an object hierarchy for a plurality of objects, each object being representative of one of a storage location or a file. The object hierarchy includes for each object, a respective node, for each object that is a parent object having a child object, a directed edge connecting the node representing the parent object. In addition, for each object, including metadata that includes an access control list identifier that identifies an access control list for the object and that is owned by an access control list root object. The method including receiving updates to an access control list for particular objects, generating a new access control list, and storing the new access control list identifier in metadata for each object that descends from the particular object.

Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for referenced access control lists. In one aspect, a method includes accessing an object hierarchy for a plurality of objects, each object being representative of one of a storage location or a file. The object hierarchy includes for each object, a respective node, for each object that is a parent object having a child object, a directed edge connecting the node representing the parent object. In addition, for each object, including metadata that includes an access control list identifier that identifies an access control list for the object and that is owned by an access control list root object. The method including receiving updates to an access control list for particular objects, generating a new access control list, and storing the new access control list identifier in metadata for each object that descends from the particular object.

Abstract: Barrier node aggregation includes: in a directed acyclic graph in which each node is defined as either a barrier node or a non-barrier node, identifying, for a first barrier node, each descendant node that is a next barrier node to the first barrier node; and aggregating, at the first barrier node, information of each non-barrier node that is a descendant of the first barrier node and not separated therefrom by any identified next barrier node. Non-barrier node propagation includes: in a directed acyclic graph in which each node is defined as either a barrier node or a non-barrier node, identifying, for a first non-barrier node, each ancestor node that is a previous barrier node to the first non-barrier node; and propagating information of the first non-barrier node to each identified previous barrier node and to each non-barrier node between the first non-barrier node and the identified previous barrier node.

Abstract: A method for retrieving information includes receiving a search query within an information corpus. Search results for the search query may be identified. A score for each of a plurality of data items identified in the search results may be generated. The score for a corresponding one of the plurality of data items may be based on a score dependent on the search query within the information corpus. The score may be also based on at least one score independent of the search query. The at least one score independent of the search query may include a ranking signal associated with a World Wide Web (WWW) search of the corresponding one of the plurality of data items using a second information corpus. The search results may be ranked based on the generated score.

Abstract: Generating and selecting recommendation explanations for personalized recommendations may include retrieving in response to at least one recommendation query, a document from a corpora of available documents for consumption by a user. The at least one recommendation query may be associated with a corresponding plurality of candidate recommendation explanations. The plurality of recommendation explanations for the document may be ranked based on popularity of at least one of the plurality of recommendation explanations when previously provided to the user and/or popularity of the document among a plurality of users under each of the plurality of recommendation explanations. The popularity of at least one of the plurality of recommendation explanations previously provided to the user may be based on document engagement history associated with the user when the at least one of the plurality of recommendation explanations were previously provided to the user.

Abstract: A method for retrieving information may include receiving, in a non-World Wide Web (WWW) corpus, a search query for a media author. Search results for the search query may be identified within the non-WWW corpus. A score for each of a plurality of media authors identified in the search results may be generated. The score for a corresponding one of the plurality of media authors may be based on a combined media popularity score for a plurality of media items authored by the corresponding one of the plurality of media authors. The search results may be ranked based on the generated score for each of the plurality of media authors.

Abstract: A method for retrieving information may include receiving, in a non-World Wide Web (WWW) corpus, a search query for a media author. Search results for the search query may be identified within the non-WWW corpus. A score for each of a plurality of media authors identified in the search results may be generated. The score for a corresponding one of the plurality of media authors may be based on a combined media popularity score for a plurality of media items authored by the corresponding one of the plurality of media authors. The search results may be ranked based on the generated score for each of the plurality of media authors.

Abstract: A method for retrieving information includes receiving a search query within an information corpus. Search results for the search query may be identified. A score for each of a plurality of data items identified in the search results may be generated. The score for a corresponding one of the plurality of data items may be based on a score dependent on the search query within the information corpus. The score may be also based on at least one score independent of the search query. The at least one score independent of the search query may include a ranking signal associated with a World Wide Web (WWW) search of the corresponding one of the plurality of data items using a second information corpus. The search results may be ranked based on the generated score.