Adaptive Distribution Method For Hash Operation

A method for joining relations, the method comprising:

• receiving a relational join query for a join operation comprising a predicate and a plurality of relations, wherein the plurality of relations comprises a first relation and a second relation;
• calculating an actual size of the second relation by processing the second relation according to a build operation;
• and
• determining whether to join the plurality of relations via a broadcasting join or a re-partitioning join based on the actual size of the second relation, an estimated size of the first relation, and a cost metric.

A system for joining relations, the system comprising non-transitory computer readable storage media storing instructions that, when executed by one or more processors, cause the one or more processors to:

• receive a relational join query for a join operation comprising a predicate and a plurality of relations, wherein the plurality of relations comprises a first relation and a second relation;
• calculate an actual size of the second relation by processing the second relation according to a build operation;
• and
• determine whether to join the plurality of relations via a broadcasting join or a re-partitioning join based on the actual seize of the second relation, an estimated size of the first relation, and a cost metric.

An apparatus for joining relations, wherein the apparatus is configured to:

• receive a relational join query for a join operation comprising a predicate and a plurality of relations, wherein the plurality of relations comprises a first relation and a second relation;
• calculate an actual size of the second relation by processing the second relation according to a build operation;
• and
• determine whether to join the plurality of relations via a broadcasting join or a re-partitioning join based on the actual size of the second relation, an estimated size of the first relation, and a cost metric.