Join processing in relational databases
ACM Computing Surveys (CSUR)
Parallel database systems: the future of high performance database systems
Communications of the ACM
Query evaluation techniques for large databases
ACM Computing Surveys (CSUR)
A high-performance parallel database architecture
ICS '93 Proceedings of the 7th international conference on Supercomputing
The art of computer programming, volume 3: (2nd ed.) sorting and searching
The art of computer programming, volume 3: (2nd ed.) sorting and searching
On optimizing an SQL-like nested query
ACM Transactions on Database Systems (TODS)
Performing Group-By before Join
Proceedings of the Tenth International Conference on Data Engineering
VLDB '87 Proceedings of the 13th International Conference on Very Large Data Bases
Translating and Optimizing SQL Queries Having Aggregates
VLDB '87 Proceedings of the 13th International Conference on Very Large Data Bases
Outstanding Challenges in OLAP
ICDE '98 Proceedings of the Fourteenth International Conference on Data Engineering
A Case for Parallelism in Data Warehousing and OLAP
DEXA '98 Proceedings of the 9th International Workshop on Database and Expert Systems Applications
Parallel Processing of "GroupBy-Before-Join" Queries in Cluster Architecture
CCGRID '01 Proceedings of the 1st International Symposium on Cluster Computing and the Grid
ISPAN '02 Proceedings of the 2002 International Symposium on Parallel Architectures, Algorithms and Networks
The use of Hints in SQL-Nested query optimization
Information Sciences: an International Journal
International Journal of Business Intelligence and Data Mining
Estimating software readiness using predictive models
Information Sciences: an International Journal
Beyond pages: supporting efficient, scalable entity search with dual-inversion index
Proceedings of the 13th International Conference on Extending Database Technology
Voronoi-based range and continuous range query processing in mobile databases
Journal of Computer and System Sciences
Data warehouse design on the basis of Hierarchical Degenerate Snowflake (HDS)
International Journal of Business Intelligence and Data Mining
Self-adaptive approximate queries for large-scale information aggregation
International Journal of Web and Grid Services
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Queries containing aggregate functions often combine multiple tables through join operations. This query is subsequently called "Groupby-Join". There is a special category of this query whereby the group-by operation can only be performed after the join operation. This is known as "Groupby-After-Join" queries--the focus of this paper. In parallel processing of such queries, it must be decided which attribute is used as a partitioning attribute, particularly join attribute or group-by attribute. Based on the partitioning attribute, two parallel processing methods, namely join partition method (JPM) and aggregate partition method (APM) are discussed. The behaviours of these parallelization methods are described in terms of cost models. Experiments are performed based on simulations. The simulation results show that the aggregate partition method performs better than the join partition method.