Processing group-by operations in databases

Abstract

The present disclosure involves methods, apparatus, and systems for processing group-by operations in databases. In one example, a method includes receiving a query to perform a group-by operation based on first attributes and second attributes of a plurality of entities. The first attributes are private data owned by a first participant of a secure multi-party computation (MPC), and the second attributes are private data owned by a second participant of the secure MPC. The method further includes mapping the first attributes to a first set of numbers, and calculating, based on secure MPC, a secret share of a dataset. The dataset includes the first set of numbers and the second attributes. The method further includes performing the group-by operation including arranging the plurality of entities into groups based on at least the first set of numbers, and aggregating the second attributes of entities in each of the groups.