Dataflow Query Execution in a Parallel, Main-memory Environment


Wilschut, A.N. and Apers, P.M.G. (1993) Dataflow Query Execution in a Parallel, Main-memory Environment. Distributed and Parallel Databases, 1 (1). pp. 103-128. ISSN 0926-8782

open access
Abstract:In this paper, the performance and characteristics of the execution of various join-trees on a parallel DBMS are studied. The results of this study are a step into the direction of the design of a query optimization strategy that is fit for parallel execution of complex queries.
Among others, synchronization issues are identified to limit the performance gain from parallelism. A new hash-join algorithm is introduced that has fewer synchronization constraints than the known hash-join algorithms. Also, the behavior of individual join operations in a join-tree is studied in a simulation experiment. The results show that the introduced Pipelining hash-join algorithm yields a better performance for multi-join queries. The format of the optimal join-tree appears to depend on the size of the operands of the join: A multi-join between small operands performs best with a bushy schedule; larger operands are better off with a linear schedule. The results from the simulation study are confirmed with an analytic model for dataflow query execution.
Item Type:Article
Additional information:Imported from EWI/DB PMS [db-utwente:arti:0000002026]
Electrical Engineering, Mathematics and Computer Science (EEMCS)
Link to this item:
Official URL:
Export this item as:BibTeX
HTML Citation
Reference Manager


Repository Staff Only: item control page