Multidimensional two-sided interval joins on hash-equality-join infrastructure

Abstract

In an embodiment, a data platform implements a two-sided N dimensional interval join using an N dimensional band join followed by a filter that applies a predicate of the interval join. The data platform generates first and second modified relations from first and second input relations. Each modified relation includes a copy of each row from the corresponding input relation for each input-domain cell that overlaps, in each of N dimensions, a bounding polygon of intervals determined from the row of the corresponding input relation. The data platform inserts, in each row in each modified relation, an input-domain-cell identifier of the corresponding overlapping input-domain cell and uses a hash-equality join that receives the first and second modified relations and that is keyed on the input-domain-cell identifiers. The data platform obtains results of a query by executing a query-execution plan that includes the query-plan section.