Decomposition of intersection and join operations based on the domain-interval fragmented column indices

Abstract

The paper presents decomposition of relational operations based on distributed column indices and domain-interval fragmentation. This decomposition admits parallel executing the resource-intensive relational operations without data transfers. All column index fragments are stored in main memory in compressed form to conserve space. During the parallel execution of relational operations, compressed index fragments are loaded on different processor cores. These cores uncompress fragments, perform relational operations and compress fragments of partial result, which is a set of keys. Partial results are merged in the resulting set of keys. DBMS use the resulting set of keys for building the resulting table. Described approach allows efficient parallel query processing for very large databases on modern computing cluster systems with many-core accelerators.