1. An enterprise database system comprising: a processor; a plurality of databases participating together as participants of an enterprise database for an enterprise, the enterprise having a plurality of enterprise domains, the enterprise database combining together objects from the plurality of enterprise domains to present a data set as being available from a single database; each database in the plurality of databases including an instance database and an associated cache, a local table, and a relationship table, wherein the instance database stores objects more frequently accessed from an enterprise domain, from among the plurality of enterprise doamins, and wherein the associated cache stores cached instances of other objects frets more frequently accessed from one or more other enterprise domains, from among the plurality of enterprise domains, but that are at least temporarily relevant within the enterprise domain, wherein the local table lists locally stored objects, including objects stored in the instance database and other objects stored in the associated cache, and wherein the relationship table indicates relationships between objects stored in the database and objects stored in the one or more other databases, the one or more other databases for different enterprise domains from among the plurality of enterprise domains; each enterprise domain including one or more database clients configured to process a query issued against the enterprise database from within the enterprise domain, including: receive a request for one or more objects stored in the enterprise database, the one or more objects identified in a query issued against the enterprise database from within the enterprise domain; refer to the local table to determine if any of the one or more requested objects are available locally in the database, including determining if any of the one or more requested objects are stored in the instance database due to being more frequently accessed from the enterprise domain or if any of the one or more requested objects are stored in the associated cache due to being at least temporarily relevant within the enterprise domain; for any of the one or more requested objects not available locally, refer to the relationship table to determine if there is a relationship between the requested object and another database from among the one or more other databases, the other database in one of the one or more other enterprise domains; for at least one object not locally available and for which the relationship table does indicate a relationship to another database, directly access the at least one object from the other enterprise domain by using a reference to the other database contained in the relationship table, directly accessing the at least one object from the other database conserving network resources; and for any of the one or more requested objects not available locally and for which the relationship table does not indicate a relationship to another individual database: query the one or more other databases to determine the location of the requested object; and query the determined location to retrieve the requested object.