1. A computer system comprising: a host configured to convey a first request to export a dataset with a first attribute, said dataset corresponding to previously backed up data; a catalog describing data stored in a deduplicating single-instance storage pool, the catalog being configured to convey a second request to retrieve a set of data objects whose data object attributes match the first attribute, in response to the first request; and a single-instance storage pool configured to store data in segments and deduplicate stored data segments, each data segment being associated with a unique fingerprint usable to distinguish one data segment from another, wherein the single-instance storage pool is further configured to: identify and re-assemble each of the set of data objects from one or more of the plurality of data segments that are associated with the set of data objects, in response to the second request; and convey the re-assembled data objects to the catalog; wherein in response to receiving the re-assembled data objects, the catalog is configured to convert the re-assembled data objects into said dataset in an archival format and store the dataset converted from the re-assembled data objects on a storage medium separate from the single-instance storage pool.