US Patent 10055422 De-duplicating results of queries of multiple data repositories

De-duplicating results of queries of data repositories is described. A system associates each data object of the first set of duplicate data objects stored by multiple data repositories with a first unique duplicate set identifier, and each data object of the second set of duplicate data objects stored by the multiple data repositories with a second unique duplicate set identifier. The system identifies a first data object of the first set of duplicate data objects and a second data object of the first set of duplicate data objects in response to a query. The system determines that the first data object is associated with the first unique duplicate set identifier, and that the second data object is also associated with the first unique duplicate set identifier. The system outputs a query result that includes only the first data object.