Attribute based file organization in a paged memory environment

Rothnie, James B.; Lozano, Tomás

doi:10.1145/360827.360831

Cited by 134 publications

(25 citation statements)

References 5 publications

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“…In [15] a non-replacement model is assumed and a formula is derived giving the expected number of block hits when blocks are randomly selected. In [9] a combination of multi-key hashing and inverted indices is proposed to achieve better clustering and less block transfers. In [t6] it is assumed that the records do not have equal probabilities to be accessed and formulae are derived giving the expected number of blocks transferred when searching a sequential or random file.…”

Section: Discussionmentioning

confidence: 99%

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Estimating disk head movement in batched searching

Manolopoulos

Kollias

1988

BIT

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Abstract.The study considers the problem of evaluating the expected disk head movement when the SCAN disk scheduling policy is used to answer a batch of queries. The two cases examined are: (a) the batched queries are based on primary key values, and (b) each query in the batch is based on secondary key values.Earlier works assumed that hit cylinders are non-distinct and derived an exact (approximate) formula for the first (second) case. In this paper, both replacement and non-replacement models are examined and new exact (exact and approximate) formulae are derived for the first (second) case. It is shown that earlier and new approximate results may be used instead of the computationally expensive exact formulae.

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Section: Discussionmentioning

confidence: 99%

“…In the next section it will be shown that formula (6) is a very close approximation of formula (8). Now we will provide a new approximate formula to be used in place of formula (9).…”

Section: P(nr Ql) ~ P(ns Q2) R = O S = O T = O ( N -1 -S -T ) P (mentioning

confidence: 98%

Estimating disk head movement in batched searching

Manolopoulos

Kollias

1988

BIT

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“…The second way is to partition the underlying space into cells (i.e., blocks) at fixed positions so that all resulting cells are of uniform size, which is the case when using the uniform grid (e.g., 13,45,59 ), also the standard indexing method for maps. Figure 2(a) is an example of a 4 × 4 uniform grid in which a collection of straight line segments has been embedded.…”

Section: Methods Based On Spatial Occupancymentioning

confidence: 99%

A sorting approach to indexing spatial data

Samet

2008

ACM SIGGRAPH 2008 Classes

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Spatial data is distinguished from conventional data by having extent. Therefore, spatial queries involve both the objects and the space that they occupy. The handling of queries that involve spatial data is facilitated by building an index on the data. The traditional role of the index is to sort the data, which means that it orders the data. However, since generally no ordering exists in dimensions greater than 1 without a transformation of the data to one dimension, the role of the sort process is one of differentiating between the data and what is usually done is to sort the spatial objects with respect to the space that they occupy. The resulting ordering is usually implicit rather than explicit so that the data need not be resorted (i.e., the index need not be rebuilt) when the queries change (e.g., the query reference objects). The index is said to order the space and the characteristics of such indexes are explored further.

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“…Val is a synthesized attribute, since its value moves up the parse tree from the leaves to the root. In Figure 18, we present a parse tree for the unsigned integer 27. Each of the nodes of the parse tree has been augmented with the attribute grammar symbols Val and Condition.…”

Section: Operating Systems Versus Database Systems -An Analogymentioning

confidence: 99%

The multi-lingual database system

Demurjian

Hsiao²

1987

1987 IEEE Third International Conference on Data Engineering

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(Continue on reveree elde If neceeeary and Identity by block number)In the past, the design and implementation of a database system has followed a rather conventional approach.First, a specific data model for the database system is chosen.Second, a corresponding model-based data language is then specified.The result of this traditional approach to the databasesystem development is a mono-lingual database system where the user sees and uses the database system with a specific data model and is model-based data language. data model and a specific model-based data language. This paper introduces a new and unconventional approach to the design and implementation of a database system, the multi-lingual database system (MLDS) . The multi-lingual database system is a single database system that can execute many transactions written respectively in different data languages and support many databases structured correspondingly in various data models.For example, this multi-lingual database system can run DL/I transactions on IMS databases, CODASYL-DML transactions on network databases, SQL transactions on relational databases and Daplex transactions on entity-relationship databases, where the system appears to the user like a heterogeneous collection of database systems. Thus, a multi-lingual database system allows the old transactions and existing databases to be migrated to the new environment, the experienced user to continue to utilize certain favorite features of existing data languages and data models, the new user to explore the strong features of the various data languages and data models, the hardware upgrade to be focused on a single system instead of a heterogeneous collection of database systems, and the database application to cover wider types of ABSTRACTIn the past, the design and implementation of a database system has followed a rather conventional approach. First, a specific data model for the database system is chosen. Second, a corresponding model-based data language is then specified. The result of this traditional approach to the database-system development is a mono-lingual database system where the user sees and uses the database system with a specific data model and its model-based data language.The conventional practice for the database-system design and implementation mandates that a database system must be restricted to a single data model and a specific model-based data language.This paper introduces a new and unconventional approach to the design and implementation of a database system, the multi-lingual database system (MLDS). The multilingual database system is a single database system that can execute many transactions written respectively in different data languages and support many databases structured correspondingly in various data models.For example, this multi-lingual database system can run DL/I transactions on IMS databases, CODASYL-DML transactions on network databases, SQL transactions on relational databases and Daplex transactions on entity-relationship database...

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Attribute based file organization in a paged memory environment

Cited by 134 publications

References 5 publications

Estimating disk head movement in batched searching

Estimating disk head movement in batched searching

A sorting approach to indexing spatial data

The multi-lingual database system

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