A prototype of an object-oriented system implemented in C_Prolog is described. Its main objective is to demonstrate system features that would support efficient management of objects and object-oriented databases in a...
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ISBN:
(纸本)0818620528
A prototype of an object-oriented system implemented in C_Prolog is described. Its main objective is to demonstrate system features that would support efficient management of objects and object-oriented databases in a persistent anddistributed environment. Mechanisms at the low level of the system were considered to support object distribution, mobility control, and configuration management in a simple and uniform way. Objects exist in clusters, which are transparent to the applications. The prototype is a framework for a self-organizing object-oriented distributed system.
Integrity constraint handling is considered an important issue in relational database management systems. Many studies were already conducted in this area. Little attention has been paid however to the influence of re...
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ISBN:
(纸本)0818620528
Integrity constraint handling is considered an important issue in relational database management systems. Many studies were already conducted in this area. Little attention has been paid however to the influence of relation fragmentation andparallelism on constraint handling. This paper shows how relation fragmentation complicates matters on the one hand, but how parallelism can help to get better efficiency in enforcing constraints on the other hand. The ideas as presented in this paper are used in the context of the PRISMA database machine; they have a more general applicability though.
The authors present a block data decomposition algorithm for two-dimensional grid problems. Their method includes local balancing to accommodate heterogeneous processors, and they characterize the conditions that must...
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The MILLIPEDE system is a small yet powerful interface of a Virtual parallel Machine (VPM) on top of distributed computing environments. MILLIPEDE is thus a convenient environment for porting various existing parallel...
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ISBN:
(纸本)0818678836
The MILLIPEDE system is a small yet powerful interface of a Virtual parallel Machine (VPM) on top of distributed computing environments. MILLIPEDE is thus a convenient environment for porting various existing parallel programming languages,for the design of new parallel programming languages, and for the development of parallel applications. MILLIPEDE is fully implemented at the Technion on a cluster of PCs running Windows-NT.(1) In this paper we briefly, describe the MILLIPEDE interface and discuss the implementation issues of several parallel languages.
This paper considers text retrieval systems which store extremely huge amounts of text while providing a multi-user retrieval service for a large customer base. Due to the severe I/O demands of such a system, it is us...
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ISBN:
(纸本)0818620528
This paper considers text retrieval systems which store extremely huge amounts of text while providing a multi-user retrieval service for a large customer base. Due to the severe I/O demands of such a system, it is usually beneficial if not necessary to utilize a multi-processor system with multiple I/O facilities in an effort to increase the parallel I/O activity, the objective being to lower search response *** defining the problem, we model a solution and show that the application can be handled in a very effective fashion by a multi-processor system with a simple LAN-based topology. The final discussion describes a type of functional splitting which, if done in a careful manner, helps improve search response time.
The problem of global synchronization in massively parallel systems is discussed for the level of models represented by asynchronous cellular automata arrays. Synchronization is called global if a given asynchronous a...
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ISBN:
(纸本)0818678704
The problem of global synchronization in massively parallel systems is discussed for the level of models represented by asynchronous cellular automata arrays. Synchronization is called global if a given asynchronous automata array functions in logical time so that its behavior can be homomorphously mapped to the behavior of the prototype synchronous system in physical time. Our approach is decomposing the asynchronous array to synchro-stratum which acts as a distributed asynchronous clock and automata stratum whose automata have a construction similar to that of the synchronous prototype array automata. For various disciplines of prototype synchronization, the corresponding variants of synchro-stratum implementation for the asynchronous analogue are discussed.
Whole array operations and array section operations are important features of many data-parallel languages. Efficient implementation of these operations on distributed-memory multicomputers is critical to the scalabil...
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ISBN:
(纸本)0818674601
Whole array operations and array section operations are important features of many data-parallel languages. Efficient implementation of these operations on distributed-memory multicomputers is critical to the scalability and high-performance of data-parallel programs. We present an approach for analyzing communication patterns induced by array operations and for scheduling message flow based on the information. Our scheduling algorithm guarantees contention-free data transfer and utilizes network resources optimally. It incurs little overhead and is suitable to be used in compilers and in runtime libraries. We also present simulation results that demonstrate the algorithm's superiority to the asynchronous transfer mode that is commonly used for this type of communication.
Algorithms for processingdistributed queries require a priori estimates of the size of intermediate relations. Most such algorithms take a “static” approach in which the algorithm is completely determined before pr...
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ISBN:
(纸本)0818620528
Algorithms for processingdistributed queries require a priori estimates of the size of intermediate relations. Most such algorithms take a “static” approach in which the algorithm is completely determined before processing begins. If size estimates are found to be inaccurate at some intermediate stage, there is no opportunity to re-schedule, and the result may be far from optimal. Adaptive query execution may be used to alleviate the problem. Care is necessary, though, to ensure that the delay associated with re-scheduling does not exceed the time saved through the use of a more efficient strategy. This paper presents a low overhead delay method to decide when to correct a strategy. Sampling is used to estimate the size of relations, and alternative heuristic strategies prepared in a background mode are used to decide when to correct. Correction is made only if lower overall delay is achieved, including correction time. Evaluation using a model of a distributed data base indicates that the heuristic strategies are near optimal. Moreover, it also suggests that it is usually correct to abort creation of an intermediate relation which is much larger than predicted.
The paper describes a preliminary evaluation of some multi-join strategies and their performances on parallel hardware. The hardware used was a Sequent (under UNIX) with 11 usable processors, each with shared and priv...
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ISBN:
(纸本)0818620528
The paper describes a preliminary evaluation of some multi-join strategies and their performances on parallel hardware. The hardware used was a Sequent (under UNIX) with 11 usable processors, each with shared and private primary memory. A multi-join was broken down into a series of single joins which were then allocated to clusters, each cluster being a collection of parallel processors. The results of single joins, which were studied by both binary search and hash-merge techniques, were then further processed as *** evaluation was conducted varying a number of parameters, such as cluster size, tuple size and cardinality. The comparative results were plotted. The study highlights the importance of a number of factors that influence the performance of a multi-join operation.
The proceedings contain 119 papers. The special focus in this conference is on parallel anddistributedprocessing and Applications. The topics include: Present and future supercomputer architectures;challenges in P2P...
ISBN:
(纸本)9783540241287
The proceedings contain 119 papers. The special focus in this conference is on parallel anddistributedprocessing and Applications. The topics include: Present and future supercomputer architectures;challenges in P2P computing;multihop wireless Ad Hoc networking: current challenges and future opportunities;an inspector-executor algorithm for irregular assignment;multi-grain parallelprocessing of data-clustering on programmable graphics hardware;a parallel reed-solomon decoder on the imagine stream processor;asynchronous document dissemination in dynamic Ad Hoc networks;location-dependent query results retrieval in a multi-cell wireless;an efficient mobile data mining model;towards correct distributed simulation of high-level petri nets with fine-grained partitioning;m-guard: a new distributed deadlock detection algorithm based on mobile agent technology;meta-based distributed computing framework;locality optimizations for jacobi iteration on distributedparallel;fault-tolerant cycle embedding in the WK-recursive network;RAIDb: redundant array of inexpensive databases;a fault-tolerant multi-agent development framework;a fault tolerance protocol for uploads: design and evaluation;topological adaptability for the distributed token circulation paradigm in faulty environment;adaptive data dissemination in wireless sensor networks;design and analysis of a k-connected topology control algorithm for Ad Hoc networks;on using temporal consistency for parallel execution of real-time queries in wireless sensor systems;cluster-based parallel simulation for large scale molecular dynamics in microscale thermophysics;parallel checkpoint/recovery on cluster of IA-64 computers;an enhanced message exchange mechanism in cluster-based mobile;a scalable low discrepancy point generator for parallel computing;generalized trellis stereo matching with systolic array.
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