Multi-dimensional clustering for data base organizations

Liou, Jeih-Jang; Yao, S. Bing

doi:10.1016/0306-4379(77)90007-2

Cited by 68 publications

(15 citation statements)

References 5 publications

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“…Most literature concerning the problem of designing an optimal multiattribute file system for partial match queries is based on the assumption that every partial match query occurs with equal probability. Lin, Lee, and Du pointed out in [4] that, among the work being done in this field, the results presented by Rivest [6] and Rothnie and Lozano [7], as well as by Liou and Yao [5], are all based on Cartesian product files. The main difference among these file systems is the way each attribute domain Di is partitioned.…”

Section: Partial Match Queries and Cartesian Product Filesmentioning

confidence: 91%

“…TDM decreases more slowly than Tw, with increase in m. The reason is that the DM allocation method allocates buckets quite efficiently and there is less improvement with increase in disks m unless the number of buckets is greatly increased. (5) Note that TDM and TRA for (ml, mz, m3) = (3, 5, 2) and(5,2,3) are equal.This shows that the average response times depend on the mi)s and not on their order.…”

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confidence: 97%

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Disk allocation for Cartesian product files on multiple-disk systems

Sobolewski

1982

ACM Trans. Database Syst.

148

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Cartesian product files have recently been shown to exhibit attractive properties for partial match queries. This paper considers the file allocation problem for Cartesian product files, which can be stated as follows: Given a k-attribute Cartesian product file and an m-disk system, allocate buckets among the m disks in such a way that, for all possible partial match queries, the concurrency of disk accesses is maximis ed. The Risk Modulo (DM) allocation method is described first, and it is shown to be strict optimal under many conditions commonly occurring in practice, including all possible partial match queries when the number of disks is 2 or 3. It is also shown that although it has good performance, the DM allocation method is not strict optimal for all possible partial match queries when the number of disks is greater than 3. The General Disk Modulo (GDM) allocation method is then described, and a sufficient but not necessary condition for strict optimal&y of the GDM method for all partial match queries and any number of disks is then derived. Simulation studies comparing the DM and random allocation methods in terms of the average number of disk accesses, in response to various classes of partial match queries, show the former to be significantly more effective even when the number of disks is greater than 3, that is, even in cases where the DM method is not strict optimal. The results that have been derived formally and shown by simulation can be used for more effective design of optimal file systems for partial match queries. When considering multiple-disk systems with independent access paths, it is important to ensure that similar records are clustered into the same or similar buckets, while similar buckets should be dispersed uniformly among the disks.

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Section: Partial Match Queries and Cartesian Product Filesmentioning

confidence: 91%

mentioning

confidence: 97%

Disk allocation for Cartesian product files on multiple-disk systems

Sobolewski

1982

ACM Trans. Database Syst.

148

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“…One such organization is the multidimensional directory suggested by Liou and Yao [17]. Attributes are ordered by priority, and numbers di, &., .…”

Section: Review Of Prior Multikey Access Techniquesmentioning

confidence: 99%

The Grid File

Nievergelt¹,

Hinterberger²,

Sevcik

1984

ACM Trans. Database Syst.

942

173

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Traditional file structures that provide multikey access to records, for example, inverted files, are extensions of file structures originally designed for single-key access. They manifest various deficiencies in particular for multikey access to highly dynamic files. We study the dynamic aspects of tile structures that treat all keys symmetrically, that is, file structures which avoid the distinction between primary and secondary keys. We start from a bitmap approach and treat the problem of file design as one of data compression of a large sparse matrix. This leads to the notions of a grid partition of the search space and of a grid directory, which are the keys to a dynamic file structure called the grid file. This tile system adapts gracefully to its contents under insertions and deletions, and thus achieves an upper hound of two disk accesses for single record retrieval; it also handles range queries and partially specified queries efficiently. We discuss in detail the design decisions that led to the grid file, present simulation results of its behavior, and compare it to other multikey access file structures.

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“…, a n ), where each a i is an occurrence of the ith attribute. 2 Thus, a pictorial database can be designed to be an MAF. Multiple key hashing (MKH) is a simple generalization of the well-known single key hashing technique to the storage and retrieval of multiple attribute records.…”

Section: Introductionmentioning

confidence: 99%