Optimizing an operator flow for performing aggregation via a database system

Abstract

A database system is operable to generate an initial query operator execution that includes an IO operator for execution serially before an aggregation operator indicating performance of an aggregation. The initial query operator execution flow is converted into an updated query operator execution flow semantically equivalent to the initial query operator execution flow based on updating the IO operator to include the performance of the aggregation and adding a re-aggregation operator serially after the IO operator. A corresponding query is executed by applying the updated query operator execution flow based on executing, via each of a plurality of parallelized resources, the IO operator generate corresponding sub-aggregation output via performance of the aggregation, and executing the re-aggregation operator upon data blocks generated based on execution of the IO operator across the plurality of parallelized resources.