The original paper is in English. Non-English content has been machine-translated and may contain typographical errors or mistranslations. ex. Some numerals are expressed as "XNUMX".
Copyrights notice
The original paper is in English. Non-English content has been machine-translated and may contain typographical errors or mistranslations. Copyrights notice
Matlamat kertas ini adalah untuk membentangkan algoritma untuk mencipta pelan pertanyaan yang dioptimumkan untuk mendapatkan maklumat maksimum daripada berbilang hubungan, menggunakan outerjoins. Terutamanya kami memberi tumpuan kepada pertanyaan konjunktif dengan kehadiran predikat dan fungsi asing. Kami menunjukkan terlebih dahulu dengan contoh bahawa mendapatkan semula maklumat maksimum dengan menyepadukan berbilang perhubungan memerlukan operator sambungan luar. Sambungan luar adalah penting untuk mengelakkan kehilangan maklumat yang akan disebabkan oleh sambungan dalam. Kami juga menunjukkan bahawa predikat dan fungsi asing berguna untuk menengahi percanggahan antara hubungan dan untuk mewujudkan pandangan sewenang-wenangnya. Outerjoins dan fungsi asing, bersama-sama dengan predikat, menyukarkan untuk membuat rancangan pemprosesan pertanyaan kerana ia mengenakan sekatan pada susunan pemprosesan pertanyaan. Selebihnya kertas ini menerangkan algoritma untuk mencipta rancangan pemprosesan pertanyaan sedemikian untuk pertanyaan konjunktif yang dinyatakan dalam Datalog lanjutan. Pertama, kami menunjukkan algoritma mudah untuk membuat rancangan pertanyaan dengan sambungan luar, tetapi tanpa predikat dan fungsi asing. Kami menggunakan perwakilan hipergraf bagi hubungan untuk menerangkan algoritma yang dioptimumkan. Kemudian, kami menunjukkan algoritma yang lebih kompleks yang berfungsi untuk rancangan pertanyaan dengan predikat dan fungsi asing. Dalam algoritma kami, kami mencipta graf ungkapan awal yang nodnya mewakili unit pemprosesan pertanyaan, termasuk operator outerjoin, predikat dan fungsi asing. Kemudian, kami menukar graf ungkapan awal menjadi pokok ekspresi yang boleh dilaksanakan dan dioptimumkan. Algoritma ini dilaksanakan dan digunakan dalam sistem pengantaraan yang menyepadukan sumber maklumat heterogen.
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Salinan
Koichi MUNAKATA, "Integration of Maximum Information Using Outerjoins, Predicates and Foreign Functions" in IEICE TRANSACTIONS on Information,
vol. E82-D, no. 1, pp. 64-75, January 1999, doi: .
Abstract: The goal of this paper is to present algorithms for creating an optimized query plan for retrieving maximum information from multiple relations, using outerjoins. Especially we focus on conjunctive queries in the presence of predicates and foreign functions. We show first with examples that retrieving maximum information by integrating multiple relations requires outerjoin operators. The outerjoin is essential to prevent information loss that would be caused by the inner join. We also show that predicates and foreign functions are useful to mediate the discrepancy among the relations and to create arbitrary views. Outerjoins and foreign functions, together with predicates, make it difficult to create query processing plans since they impose restrictions on the order of query processing. The rest of this paper describes algorithms for creating such query processing plans for conjunctive queries expressed in extended Datalog. First, we show simple algorithms for creating query plans with outerjoins, but without predicates and foreign functions. We use the hypergraph representation of the relations to explain an optimized algorithm. Then, we show a more complex algorithm that works for query plans with predicates and foreign functions. In our algorithm, we create an initial expression graph whose nodes represent query processing units, including outerjoin, predicate and foreign function operators. Then, we convert the initial expression graph into an executable, optimized expression tree. This algorithm is implemented and deployed in a mediation system that integrates heterogeneous information sources.
URL: https://global.ieice.org/en_transactions/information/10.1587/e82-d_1_64/_p
Salinan
@ARTICLE{e82-d_1_64,
author={Koichi MUNAKATA, },
journal={IEICE TRANSACTIONS on Information},
title={Integration of Maximum Information Using Outerjoins, Predicates and Foreign Functions},
year={1999},
volume={E82-D},
number={1},
pages={64-75},
abstract={The goal of this paper is to present algorithms for creating an optimized query plan for retrieving maximum information from multiple relations, using outerjoins. Especially we focus on conjunctive queries in the presence of predicates and foreign functions. We show first with examples that retrieving maximum information by integrating multiple relations requires outerjoin operators. The outerjoin is essential to prevent information loss that would be caused by the inner join. We also show that predicates and foreign functions are useful to mediate the discrepancy among the relations and to create arbitrary views. Outerjoins and foreign functions, together with predicates, make it difficult to create query processing plans since they impose restrictions on the order of query processing. The rest of this paper describes algorithms for creating such query processing plans for conjunctive queries expressed in extended Datalog. First, we show simple algorithms for creating query plans with outerjoins, but without predicates and foreign functions. We use the hypergraph representation of the relations to explain an optimized algorithm. Then, we show a more complex algorithm that works for query plans with predicates and foreign functions. In our algorithm, we create an initial expression graph whose nodes represent query processing units, including outerjoin, predicate and foreign function operators. Then, we convert the initial expression graph into an executable, optimized expression tree. This algorithm is implemented and deployed in a mediation system that integrates heterogeneous information sources.},
keywords={},
doi={},
ISSN={},
month={January},}
Salinan
TY - JOUR
TI - Integration of Maximum Information Using Outerjoins, Predicates and Foreign Functions
T2 - IEICE TRANSACTIONS on Information
SP - 64
EP - 75
AU - Koichi MUNAKATA
PY - 1999
DO -
JO - IEICE TRANSACTIONS on Information
SN -
VL - E82-D
IS - 1
JA - IEICE TRANSACTIONS on Information
Y1 - January 1999
AB - The goal of this paper is to present algorithms for creating an optimized query plan for retrieving maximum information from multiple relations, using outerjoins. Especially we focus on conjunctive queries in the presence of predicates and foreign functions. We show first with examples that retrieving maximum information by integrating multiple relations requires outerjoin operators. The outerjoin is essential to prevent information loss that would be caused by the inner join. We also show that predicates and foreign functions are useful to mediate the discrepancy among the relations and to create arbitrary views. Outerjoins and foreign functions, together with predicates, make it difficult to create query processing plans since they impose restrictions on the order of query processing. The rest of this paper describes algorithms for creating such query processing plans for conjunctive queries expressed in extended Datalog. First, we show simple algorithms for creating query plans with outerjoins, but without predicates and foreign functions. We use the hypergraph representation of the relations to explain an optimized algorithm. Then, we show a more complex algorithm that works for query plans with predicates and foreign functions. In our algorithm, we create an initial expression graph whose nodes represent query processing units, including outerjoin, predicate and foreign function operators. Then, we convert the initial expression graph into an executable, optimized expression tree. This algorithm is implemented and deployed in a mediation system that integrates heterogeneous information sources.
ER -