Validated Cost Models for Parallel OQL Query Processing

Sampaio, Sandra; Paton, Norman W.; Smith, Jim; Watson, Paul

doi:10.1007/3-540-46102-7_10

Cited by 9 publications

(6 citation statements)

References 10 publications

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“…The parallel execution of operators is always load balanced. The cost model in [28], which is a detailed and validated one developed for parallel object database systems, has been adapted to operate in a distributed and autonomous environment and has been incorporated in the query engine. This model estimates the query completion time, by estimating the cost of each operator instance separately in time units.…”

Section: Discussionmentioning

confidence: 99%

“…TimeCost(G) (or TimeCost(QueryPlan)) is the time cost of the plan, while TimeCost(V i ) is the time cost of operator V i . Note that typically, cost models estimate the cost of a query plan by estimating the cost model of individual operators and taking into account any parallelism if appropriate (e.g., [28]). Thus, the same cost model is responsible for the calculation of TimeCost(G) and TimeCost(V i ).…”

Section: Notationmentioning

confidence: 99%

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A novel approach to resource scheduling for parallel query processing on computational grids

Gounaris

Sakellariou

Paton

et al. 2006

Distrib Parallel Databases

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Advances in network technologies and the emergence of Grid computing have both increased the need and provided the infrastructure for computation and data intensive applications to run over collections of heterogeneous and autonomous nodes. In the context of database query processing, existing parallelisation techniques cannot operate well in Grid environments because the way they select machines and allocate tasks compromises partitioned parallelism. The main contribution of this paper is the proposal of a low-complexity, practical resource selection and scheduling algorithm that enables queries to employ partitioned parallelism, in order to achieve better performance in a Grid setting. The evaluation results show that the scheduler proposed outperforms current techniques without sacrificing the efficiency of resource utilisation.

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Section: Discussionmentioning

confidence: 99%

Section: Notationmentioning

confidence: 99%

A novel approach to resource scheduling for parallel query processing on computational grids

Gounaris

Sakellariou

Paton

et al. 2006

Distrib Parallel Databases

Self Cite

View full text Add to dashboard Cite

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“…Results are presented for queries running over the medium 007 database [3], the most widely used object database benchmark.The experiments and the resulting performance figures can be seen to serve two purposes: (i) they provide insights on algorithm selection for implementers of parallel object databases; (ii) they provide empirical results against which cost models for parallel query processing can be validated (e.g. [4,5]). The development of cost models for query performance is a well-established activity.…”

mentioning

confidence: 99%

“…The experiments and the resulting performance figures can be seen to serve two purposes: (i) they provide insights on algorithm selection for implementers of parallel object databases; (ii) they provide empirical results against which cost models for parallel query processing can be validated (e.g. [4,5]).…”

mentioning

confidence: 99%

Measuring and modelling the performance of a parallel ODMG compliant object database server

Sampaio

Paton

Smith

et al. 2005

Concurrency and Computation

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SUMMARYObject database management systems (ODBMSs) are now established as the database management technology of choice for a range of challenging data intensive applications. Furthermore, the applications associated with object databases typically have stringent performance requirements, and some are associated with very large data sets. An important feature for the performance of object databases is the speed at which relationships can be explored. In queries, this depends on the effectiveness of different join algorithms into which queries that follow relationships can be compiled. This paper presents a performance evaluation of the Polar parallel object database system, focusing in particular on the performance of parallel join algorithms. Polar is a parallel, shared-nothing implementation of the Object Database Management Group (ODMG) standard for object databases. The paper presents an empirical evaluation of queries expressed in the ODMG Query Language (OQL), as well as a cost model for the parallel algebra that is used to evaluate OQL queries. The cost model is validated against the empirical results for a collection of queries using four different join algorithms, one that is value based and three that are pointer based.

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“…The parallel execution of operators is always load balanced. The cost model in [10], which is a detailed and validated one developed for parallel object database systems, has been adapted to operate in a distributed and autonomous environment and has been incorporated in the query engine. This model estimates the query completion time, by estimating the cost of each operator separately in time units.…”

Section: Discussionmentioning

confidence: 99%