Accessing a primary clustery key index structure during query execution

A computer readable memory device comprises:

• at least one memory section that stores operational instructions that, when executed by a set of processing core resources of a computing device cluster of a database system, causes the set of processing core resources to:
• receive a query regarding a dataset, wherein the dataset includes a plurality of rows of columnar data, wherein:
• the dataset is divided into a plurality of segments,
• a first segment of the plurality of segments includes a first sub-set of rows of columnar data of the plurality of rows of columnar data,
• the first sub-set of rows are organized in accordance with a primary cluster key,
• a first secondary index structure is created for the first segment based on a secondary index, wherein the secondary index identifies rows of the dataset that include data values of interest;
• the first segment and the first secondary index structure are stored in accordance with a long-term storage (LTS) protocol;
• generate, in accordance with executing the query, a plurality of input/output (IO) pipelines, wherein each IO pipeline of the plurality of IO pipelines includes a secondary index element and a primary key element, and wherein a first IO pipeline of the plurality of IO pipelines is associated with the first processing core resource;
• retrieve, in accordance with executing the query, the first segment by the secondary index element of the first IO pipeline in accordance with the first secondary index structure to produce first retrieved indexed rows of the first segment;
• filter, in accordance with executing the query and based on a secondary filtering condition of the query, the first retrieved indexed rows of the first segment by the secondary index element of the first IO pipeline to produce first filtered indexed rows of the first segment;
• and
• process, in accordance with executing the query, the first filter indexed rows of the first segment by the primary key element of the first IO pipeline in accordance with the primary key and the LTS protocol to produce first raw, filtered, indexed rows of the first segment, wherein the database system includes:
• a plurality of computing device clusters, wherein the computing device cluster of the plurality of computing device clusters includes a plurality of computing devices, wherein a computing device of the plurality of computing devices includes a plurality of computing nodes, wherein a computing node of the plurality of computing nodes includes a plurality of processing core resources.