Database management systems will continue to manage large data volumes. Thus, efficient algorithms for accessing and manipulating large sets and sequences will be required to provide acceptable performance. The advent of object-oriented and extensible database systems will not solve this problem. On the contrary, modern data models exacerbate the problem: In order to manipulate large sets of complex objects as efficiently as today's database systems manipulate simple records, query-processing algorithms and software will become more complex, and a solid understanding of algorithm and architectural issues is essential for the designer of database management software. This survey provides a foundation for the design and implementation of query execution facilities in new database management systems. It describes a wide array of practical query evaluation techniques for both relational and postrelational database systems, including iterative execution of complex query evaluation plans, the duality of sort- and hash-based set-matching algorithms, types of parallel query execution and their implementation, and special operators for emerging database application domains.

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Query evaluation techniques for large databases

The join operation is one of the fundamental relational database query operations. It facilitates the retrieval of information from two different relations based on a Cartesian product of the two relations. The join is one of the most diffidult operations to implement efficiently, as no predefined links between relations are required to exist (as they are with network and hierarchical systems). The join is the only relational algebra operation that allows the combining of related tuples from relations on different attribute schemes. Since it is executed frequently and is expensive, much research effort has been applied to the optimization of join processing. In this paper, the different kinds of joins and the various implementation techniques are surveyed. These different methods are classified based on how they partition tuples from different relations. Some require that all tuples from one be compared to all tuples from another; other algorithms only compare some tuples from each. In addition, some techniques perform an explicit partitioning, whereas others are implicit.

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Join processing in relational databases

In one aspect of the present invention, a network gateway is configured to facilitate on line and off line bi-directional communication between a number of near end data and telephony devices with far end data termination devices via a hybrid fiber coaxial network and a cable modem termination system. The described network gateway combines a QAM receiver, a transmitter, a DOCSIS MAC, a CPU, a voice and audio processor, an Ethernet MAC, and a USB controller to provide high performance and robust operation.

Gateway with voice

Are there cultural differences in learning style

Logic and databases have gone a long way together since the advent of relational databases. Already the first basic query languages for relational databases beside relational algebra — tuple calculus and domain calculus — are actually a subset of first order predicate logic. Furthermore logic proved to be very adequate for establishing a sound theory for relational databases.

Logic and databases

Electronic voting systems: Requirements, design, and implementation

Although there are many studies addressing the relationship of learning style to outcomes in engineering courses, few have attempted direct cross-cultural comparisons. This study investigates similarities and differences in the learning styles of computer science and engineering students at a Middle Eastern institution and an American university in the Midwestern United States. Comparative data on student learning style profiles and course outcomes suggest that, despite vast cultural differences, strong similarities exist between learning styles of these students. Seemingly, a consistent pattern in how these students learn across cultures also exists. These findings have significant implications for the creation of globally effective teaching materials

Learning Styles of Computer Programming Students: A Middle Eastern and American Comparison

The problem of extracting sentiments from text is a very complex task, in particular due to the significant amount of Natural Language Processing (NLP) required. This task becomes even more difficult when dealing with morphologically rich languages such as Modern Standard Arabic (MSA) and when processing brief, noisy texts such as “tweets” or “Facebook statuses”. This paper highlights key issues researchers are facing and innovative approaches that have been developed when performing subjectivity and sentiment analysis (SSA) on Arabic text in general and Arabic social media text in particular. A preprocessing phase to sentiment analysis is proposed and shown to noticeably improve the results of sentiment extraction from Arabic social media data.

Key issues in conducting sentiment analysis on Arabic social media text

A transitive closure operator will be an important new operator in future deductive database systems. We discuss the compilation of recursive rule clusters into formulas containing transitive closure operations and study three promising algorithms for the processing of transitive closure queries: the wavefront algorithm, the δ-wavefront algorithm and the level-relaxed δ-wavefront algorithm. The relative processing efficiency of these algorithms are analyzed and compared based on different database structures and accessing methods. Our study shows that the δ-wavefront algorithm performs consistently better than the wavefront algorithm, and the level-relaxed δ-wavefront algorithm has high potential of further reducing I/O accessing cost on the databases with clustered derivation paths. The study also provides some interesting heuristics on the database structures and implementation techniques in the processing of recursive database queries.

The Processing and Evaluation of Transitive Closure Queries

The authors develop and present a large set of parallel algorithms for implementing the join operation on a shared-memory multiprocessor database machine. The development of these algorithms follows a structured approach. The major steps involved in the processing of the join operation by the machine are first identified. Then, alternative join algorithms are constructed by concatenating the different ways of performing these steps. A study of the performance of the proposed algorithms is presented. This study shows, among other things, that for a given hardware configuration there is not just one overall best performing join algorithm, but rather different algorithms score the best performance, depending on the characteristics of the data participating in the join operation. >

Ghassan Z. Qadah

Papers

Electronic voting systems: Requirements, design, and implementation

Learning Styles of Computer Programming Students: A Middle Eastern and American Comparison

Key issues in conducting sentiment analysis on Arabic social media text

The Processing and Evaluation of Transitive Closure Queries

The join algorithms on a shared-memory multiprocessor database machine