Cost-Driven Evaluation of Vertical Class Partitioning in Object Oriented Databases

Fung, Chi-Wai; Karlapalem, Kamalakar; Li, Qing

doi:10.1142/9789812819536_0002

Cited by 12 publications

(12 citation statements)

References 6 publications

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“…As affinity-based approach does not model the size of the instance variables/objects, but this is a very important factor in the query processing cost, this is especially the case in multimedia database applications where the instance variables have highly varied sizes. Our cost-based approach do model the size of instance variables/objects and in [7], we have shown that cost-driven approach outperforms the affinity-based approach. In this paper, we aim at a more comprehensive cost model which encompasses both class composition hierarchy and subclass hierarchy.…”

Section: Related Workmentioning

confidence: 84%

“…Although significant research has been conducted within the context of cost models for query processing in unpartitioned cases (e.g., see [9]), there is very little work on detailed cost analysis of query processing for the vertically partitioned OODBMS. In [7], we presented a preliminary cost model to study the effectiveness of vertical partitioning in OODB in terms of reducing the number of disk accesses for query processing. We show that there is an optimal number of vertical fragments for a class collection, which can give rise to substantial savings in number of disk accesses.…”

Section: Related Workmentioning

confidence: 99%

“…Further, we showed that the cardinality of the class does not impact the proportion of the reduction in the number of disk accesses incurred, implying that as the cardinality of the classes increase the IO savings will also proportionally increase. However, in [7], we have ignored for simplicity the extra processing for dealing with the composite objects generated from vertical partitioning, instead, the main focus there was on comparing the two approaches to vertical partitioning namely, affinity-based and cost-driven. As affinity-based approach does not model the size of the instance variables/objects, but this is a very important factor in the query processing cost, this is especially the case in multimedia database applications where the instance variables have highly varied sizes.…”

Section: Related Workmentioning

confidence: 99%

“…The following vertical partitioning schemes are the optimal vertical partition schemes obtained from our previous theoretical work [7] …”

Section: Vertical Partitioning Schemementioning

confidence: 99%

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An evaluation of vertical class partitioning for query processing in object-oriented databases

Fung¹,

Karlapalem²,

Li³

2002

IEEE Trans. Knowl. Data Eng.

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Abstract--Vertical partitioning is a design technique for reducing the number of disk accesses to execute a given set of queries by minimizing the number of irrelevant instance variables accessed. This is accomplished by grouping the frequently accessed instance variables as vertical class fragments. The complexity of object-oriented database models due to subclass hierarchy and class composition hierarchy complicates the definition and representation of vertical partitioning of the classes, which makes the problem of vertical partitioning in OODBs very challenging. In this paper, we develop a comprehensive analytical cost model for processing of queries on vertically partitioned OODB classes. A set of analytical evaluation results is presented to show the effect of vertical partitioning, and to study the trade-off between projection ratio vs. selectivity factor vis-a-vis sequential vs. index access. Furthermore, an empirical experimental prototype supporting vertical class partitioning has been implemented on a commercial OODB tool kit to validate our analytical cost model.

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Section: Related Workmentioning

confidence: 84%

Section: Related Workmentioning

confidence: 99%

Section: Related Workmentioning

confidence: 99%

“…The following vertical partitioning schemes are the optimal vertical partition schemes obtained from our previous theoretical work [7] …”

Section: Vertical Partitioning Schemementioning

confidence: 99%

See 2 more Smart Citations

An evaluation of vertical class partitioning for query processing in object-oriented databases

Fung¹,

Karlapalem²,

Li³

2002

IEEE Trans. Knowl. Data Eng.

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“…Table 1 presents the basic cost model parameters, some of the parameter values used are taken from [17,2,15,19,9,1,6,7,8]. To better compare with previous work and evaluate the usefulness of the different indices in SJIH, as in [15,19], we neglect the disk access cost for evaluating the predicates, which is assumed to be the same for the different indices.…”

Section: Cost Model For Evaluating Sjihmentioning

confidence: 99%

Complex object retrieval via structural join index hierarchy mechanisms

Fung

Karlapalem

2000

Proceedings of the Ninth International Conference on Information and Knowledge Management

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In this paper, we introduce structural join index hierarchy (SJIH) mechanisms that mimic the class composition hierarchy of the complex objects to provide direct access to complex objects and/or their component objects. SJIH extends the work on join index hierarchies by providing efficient and flexible access to complex objects, thus unifying various previous indexing methods proposed for object oriented database (OODB). A cost model for processing the queries and maintaining the indices is developed. A heuristic algorithm is designed to select appropriate indices to efficiently process a given set of queries. We show that SJIH indexing mechanisms facilitate efficient retrieval of complex objects. Given a set of queries and a limited index storage space, the heuristic algorithm facilitates fast selection of near-optimal set of indices for efficiently executing the queries.

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