Abstract: A method includes receiving a query that that is unstructured for a plurality databases; receiving data identifying resources that are determined to be responsive to the query, each resource associated with a search score that defines a respective position of the resource in an order of responsiveness to the query; determining, a service requirement from the terms of the query; determining, for each of the databases, a service requirement score for the database; for each resource that is associated with one of the databases, adjusting the search score based on the service requirement score for the database; generating search results, each search result identify a corresponding resource that was determined to be responsive to the query, and the search results being ordered according to the respective search scores and adjusted search scores of the resources.

Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for identifying entities that are related to an entity to which a search query is directed. One of the methods includes receiving a search query, wherein the search query has been determined to relate to a first entity of a first entity type, and wherein one or more entities of a second entity type have a relationship with the first entity; receiving search results for the search query; determining that a count of search results identifying a resource containing a reference to the first entity satisfies a first threshold value; determining that a count of search results identifying a resource having the second entity type as a relevant entity type satisfies a second threshold value; and transmitting information identifying the one or more entities of the second entity type as part of the response to the search query.

Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for receiving a first search query from a user device; receiving search results for the first search query provided by a search engine, wherein each of the search results identifies a respective resource; determining from the search results that the first search query relates to a first entity of a first entity type; determining that one or more entities of a second entity type have a predetermined relationship with the first entity; and transmitting information identifying the one or more entities of the second type to the user device as part of a response to the first search query.