Spilling a hash set structure to disk in conjunction with executing a set operation via a database system

Abstract

A database system is operable to, in response to the spill to disk condition being met, spill a hash set structure to disk based on partitioning a set of hash values of the hash set structure into a plurality of hash buckets written to disk memory resources. Each of a remaining incoming subset of input rows of a plurality of input rows are processed while the spill to disk condition is met based on storing an un-hashed row value of the each of the remaining incoming subset of input rows into one of a plurality of row buckets written to the disk memory resources. In response completing processing of all of the plurality of input rows, output rows of an output row set are generated based on processing the plurality of hash buckets and the plurality of row buckets.