Embodiments of the present invention relate to systems, methods, and computer-storage media for affinitizing datasets based on efficient query processing. In one embodiment, a plurality of datasets within a data stream is received. The data stream is partitioned based on efficient query processing. Once the data stream is partitioned, an affinity identifier is assigned to datasets based on the partitioning of the dataset. Further, when datasets are broken into extents, the affinity identifier of the parent dataset is retained in the resulting extent. The affinity identifier of each extent is then referenced to preferentially store extents having common affinity identifiers within close proximity of one other across a data center.