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Equivalence of Keyed Relational Schemas by Conjunctive Queries

Joseph Albert, Yannis Ioannidis, Raghu Ramakrishnan
<span title="">1999</span> <i title="Elsevier BV"> <a target="_blank" rel="noopener" href="https://fatcat.wiki/container/p6ovb2qpkfenhmb7mcksobrcxq" style="color: black;">Journal of computer and system sciences (Print)</a> </i> &nbsp;
In this work, we resolve the conjecture in the affirmative for the case of query equivalence based on mappings using conjunctive relational queries with equality selections.  ...  An important notion of schema equivalence, query equivalence, was introduced by Atzeni et al., and used to evaluate the correctness of schema transformations.  ...  ACKNOWLEDGMENTS The authors thank Rick Hull, the PODS-97 program committee members, and the anonymous referees for their insightful commentaries on earlier versions of this paper.  ... 
<span class="external-identifiers"> <a target="_blank" rel="external noopener noreferrer" href="https://doi.org/10.1006/jcss.1999.1628">doi:10.1006/jcss.1999.1628</a> <a target="_blank" rel="external noopener" href="https://fatcat.wiki/release/2wrpbubckzfzfmlaj5sygcyb7e">fatcat:2wrpbubckzfzfmlaj5sygcyb7e</a> </span>
<a target="_blank" rel="noopener" href="https://web.archive.org/web/20170828234136/http://www.madgik.di.uoa.gr/sites/default/files/jcss_v58.3.pp512-534.pdf" title="fulltext PDF download" data-goatcounter-click="serp-fulltext" data-goatcounter-title="serp-fulltext"> <button class="ui simple right pointing dropdown compact black labeled icon button serp-button"> <i class="icon ia-icon"></i> Web Archive [PDF] <div class="menu fulltext-thumbnail"> <img src="https://blobs.fatcat.wiki/thumbnail/pdf/67/22/67225b55a4fbd58eab4a013c808b7d0007adc01c.180px.jpg" alt="fulltext thumbnail" loading="lazy"> </div> </button> </a> <a target="_blank" rel="external noopener noreferrer" href="https://doi.org/10.1006/jcss.1999.1628"> <button class="ui left aligned compact blue labeled icon button serp-button"> <i class="external alternate icon"></i> Publisher / doi.org </button> </a>

Conjunctive query equivalence of keyed relational schemas (extended abstract)

Joseph Albert, Yanis Ioannidis, Raghu Ramakrishnan
<span title="">1997</span> <i title="ACM Press"> <a target="_blank" rel="noopener" href="https://fatcat.wiki/container/xtq6wnwaszaebg4qf7aw6mllwi" style="color: black;">Proceedings of the sixteenth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems - PODS &#39;97</a> </i> &nbsp;
In this work, we resolve the conjecture in the affirmative for the case of query equivalence based on mappings using conjunctive relational queries with equality selections.  ...  An important notion of schema equivalence, query equivalence was introduced in [3], and used to evaluate the correctness of schema transformations.  ...  Acknowledgements The authors would like to thank Rick Hull for the insightful commentary that he provided on an earlier draft of this Paw.  ... 
<span class="external-identifiers"> <a target="_blank" rel="external noopener noreferrer" href="https://doi.org/10.1145/263661.263667">doi:10.1145/263661.263667</a> <a target="_blank" rel="external noopener" href="https://dblp.org/rec/conf/pods/AlbertIR97.html">dblp:conf/pods/AlbertIR97</a> <a target="_blank" rel="external noopener" href="https://fatcat.wiki/release/hyi4dkcxs5e65araajeafg7llm">fatcat:hyi4dkcxs5e65araajeafg7llm</a> </span>
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Page 2829 of Mathematical Reviews Vol. , Issue 89E [page]

<span title="">1989</span> <i title="American Mathematical Society"> <a target="_blank" rel="noopener" href="https://archive.org/details/pub_mathematical-reviews" style="color: black;">Mathematical Reviews </a> </i> &nbsp;
The authors deal with the problem of describing formally all keys of relational schemes.  ...  a relational schema.  ... 
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Consistent Answers of Conjunctive Queries on Graphs [article]

Foto N. Afrati, Phokion G. Kolaitis, Angelos Vasilakopoulos
<span title="2015-03-02">2015</span> <i > arXiv </i> &nbsp; <span class="release-stage" >pre-print</span>
In this paper, we study the consistent answers of Boolean conjunctive queries involving a single binary relation, i.e., we consider arbitrary Boolean conjunctive queries on directed graphs.  ...  During the past decade, there has been an extensive investigation of the computational complexity of the consistent answers of Boolean conjunctive queries under primary key constraints.  ...  Conjunctive-Query Equivalence under a Key Constraint We will analyze conjunctive-query equivalence under the key constraint of the binary relation symbol R.  ... 
<span class="external-identifiers"> <a target="_blank" rel="external noopener" href="https://arxiv.org/abs/1503.00650v1">arXiv:1503.00650v1</a> <a target="_blank" rel="external noopener" href="https://fatcat.wiki/release/gqmcu745n5h3zmwwzznu56p6gy">fatcat:gqmcu745n5h3zmwwzznu56p6gy</a> </span>
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Efficient XML-to-SQL Query TranslationWhere to Add the Intelligence? [chapter]

R KRISHNAMURTHY, R KAUSHIK, J NAUGHTON
<span title="">2004</span> <i title="Elsevier"> Proceedings 2004 VLDB Conference </i> &nbsp;
We consider the efficiency of queries generated by XML to SQL translation.  ...  We first show that published XML-to-SQL query translation algorithms are suboptimal in that they often translate simple path expressions into complex SQL queries even when much simpler equivalent SQL queries  ...  The relational query keyQuery(N S) is the same as Query(N S), except that the key column(s) of Rel(n k ) is (are) also projected. Query(N S) and keyQuery(N S) are always conjunctive queries.  ... 
<span class="external-identifiers"> <a target="_blank" rel="external noopener noreferrer" href="https://doi.org/10.1016/b978-012088469-8/50016-4">doi:10.1016/b978-012088469-8/50016-4</a> <a target="_blank" rel="external noopener" href="https://fatcat.wiki/release/p3i6uzqccfhgpbgx3uqp4nxqnu">fatcat:p3i6uzqccfhgpbgx3uqp4nxqnu</a> </span>
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Page 4768 of Mathematical Reviews Vol. , Issue 90H [page]

<span title="">1990</span> <i title="American Mathematical Society"> <a target="_blank" rel="noopener" href="https://archive.org/details/pub_mathematical-reviews" style="color: black;">Mathematical Reviews </a> </i> &nbsp;
90h:68034 68 queries equivalent to a given relational calculus conjunctive query in which every relation schema participates at most once.  ...  (Note that the equivalence algorithms for these conjunctive queries are polynomial.)  ... 
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Axiomatic Foundations and Algorithms for Deciding Semantic Equivalences of SQL Queries [article]

Shumo Chu, Brendan Murphy, Jared Roesch, Alvin Cheung, Dan Suciu
<span title="2018-05-24">2018</span> <i > arXiv </i> &nbsp; <span class="release-stage" >pre-print</span>
Deciding the equivalence of SQL queries is a fundamental problem in data management.  ...  In this paper, we present a new formalism and implementation for reasoning about the equivalences of SQL queries.  ...  RELATED WORK Containment and equivalence of relational queries. Relational query containment and equivalence is a well studied topic in data management research.  ... 
<span class="external-identifiers"> <a target="_blank" rel="external noopener" href="https://arxiv.org/abs/1802.02229v3">arXiv:1802.02229v3</a> <a target="_blank" rel="external noopener" href="https://fatcat.wiki/release/7yrsjq6ho5aondzy7kkoc5niii">fatcat:7yrsjq6ho5aondzy7kkoc5niii</a> </span>
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Page 5763 of Mathematical Reviews Vol. , Issue 2000h [page]

<span title="">2000</span> <i title="American Mathematical Society"> <a target="_blank" rel="noopener" href="https://archive.org/details/pub_mathematical-reviews" style="color: black;">Mathematical Reviews </a> </i> &nbsp;
for keys of a database relation schema.  ...  Also, the concept of tableaux gives a proof procedure for computing all keys of a relation schema.  ... 
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An Efficient Computation of Frequent Queries in a Star Schema [chapter]

Cheikh Tidiane Dieng, Tao-Yuan Jen, Dominique Laurent
<span title="">2010</span> <i title="Springer Berlin Heidelberg"> <a target="_blank" rel="noopener" href="https://fatcat.wiki/container/2w3awgokqne6te4nvlofavy5a4" style="color: black;">Lecture Notes in Computer Science</a> </i> &nbsp;
frequent conjunctive queries becomes feasible for databases operating over a star schema.  ...  Although the problem of computing frequent queries in relational databases is known to be intractable, it has been argued in our previous work that using functional and inclusion dependencies, computing  ...  foreign keys, and (ii) selection conditions of the form (Y = Y ′ ) where Y and Y ′ are relation schemas are allowed in [7] , which is not the case in our approach.  ... 
<span class="external-identifiers"> <a target="_blank" rel="external noopener noreferrer" href="https://doi.org/10.1007/978-3-642-15251-1_18">doi:10.1007/978-3-642-15251-1_18</a> <a target="_blank" rel="external noopener" href="https://fatcat.wiki/release/gnvqxqgkzjbsbpuyw2iipfxray">fatcat:gnvqxqgkzjbsbpuyw2iipfxray</a> </span>
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Containment and Minimization of RDF/S Query Patterns [chapter]

Giorgos Serfiotis, Ioanna Koffina, Vassilis Christophides, Val Tannen
<span title="">2005</span> <i title="Springer Berlin Heidelberg"> <a target="_blank" rel="noopener" href="https://fatcat.wiki/container/2w3awgokqne6te4nvlofavy5a4" style="color: black;">Lecture Notes in Computer Science</a> </i> &nbsp;
More precisely, we consider two widely used RDF/S query fragments supporting pattern matching at the data, but also, at the schema level.  ...  In this paper, we present sound and complete algorithms for the containment and minimization of RDF/S query patterns.  ...  Acknowledgements We would like to thank Alin Deutsch and Nicola Onose for fruitful discussions on relational and XML SQO.  ... 
<span class="external-identifiers"> <a target="_blank" rel="external noopener noreferrer" href="https://doi.org/10.1007/11574620_44">doi:10.1007/11574620_44</a> <a target="_blank" rel="external noopener" href="https://fatcat.wiki/release/hv5f6blgxfbinjvlsy2m4ntk64">fatcat:hv5f6blgxfbinjvlsy2m4ntk64</a> </span>
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Query reformulation with constraints

Alin Deutsch, Lucian Popa, Val Tannen
<span title="2006-03-01">2006</span> <i title="Association for Computing Machinery (ACM)"> <a target="_blank" rel="noopener" href="https://fatcat.wiki/container/svqjiw2cwzftpcod3duuxcbveu" style="color: black;">SIGMOD record</a> </i> &nbsp;
In fact, we had already shown in [11] that C&B will find all reformulations of conjunctive queries using conjunctive views, if such reformulations exists.  ...  Let Σ 1 , Σ 2 be two schemas, which may overlap, C be a set of constraints on the joint schema Σ 1 ∪ Σ 2 , and q 1 be a Σ 1 -query.  ...  Thus, given conjunctive Σ 1 -query q and set of constraints C over Σ 1 , the problem of finding all total conjunctive query rewritings of q reduces to finding all minimal reformulations of q against schema  ... 
<span class="external-identifiers"> <a target="_blank" rel="external noopener noreferrer" href="https://doi.org/10.1145/1121995.1122010">doi:10.1145/1121995.1122010</a> <a target="_blank" rel="external noopener" href="https://fatcat.wiki/release/4idubwtzdbhq5do6thbf2symii">fatcat:4idubwtzdbhq5do6thbf2symii</a> </span>
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HoTTSQL: Proving Query Rewrites with Univalent SQL Semantics [article]

Shumo Chu, Konstantin Weitz, Alvin Cheung, Dan Suciu
<span title="2016-08-05">2016</span> <i > arXiv </i> &nbsp; <span class="release-stage" >pre-print</span>
In addition, while query equivalence is generally undecidable, we have implemented an automated decision procedure using HoTTSQL for conjunctive queries: a well-studied decidable fragment of SQL that encompasses  ...  Part of the challenges comes from the intricacies and rich features of query languages, which makes reasoning about rewrite rules difficult.  ...  conjunctive queries represent a fragment of SQL where equivalence is decidable.  ... 
<span class="external-identifiers"> <a target="_blank" rel="external noopener" href="https://arxiv.org/abs/1607.04822v2">arXiv:1607.04822v2</a> <a target="_blank" rel="external noopener" href="https://fatcat.wiki/release/rg2w2phqrrhcvjnz53q425us6u">fatcat:rg2w2phqrrhcvjnz53q425us6u</a> </span>
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HoTTSQL: proving query rewrites with univalent SQL semantics

Shumo Chu, Konstantin Weitz, Alvin Cheung, Dan Suciu
<span title="">2017</span> <i title="ACM Press"> <a target="_blank" rel="noopener" href="https://fatcat.wiki/container/jpubwsjaozha5itdes6pzyz2fm" style="color: black;">Proceedings of the 38th ACM SIGPLAN Conference on Programming Language Design and Implementation - PLDI 2017</a> </i> &nbsp;
In addition, while query equivalence is generally undecidable, we have implemented an automated decision procedure using HoTT SQL for conjunctive queries: a well-studied decidable fragment of SQL that  ...  Part of the challenges comes from the intricacies and rich features of query languages, which makes reasoning about rewrite rules difficult.  ...  HoTT SQL query that projects on the a key of the relation and the index attribute.  ... 
<span class="external-identifiers"> <a target="_blank" rel="external noopener noreferrer" href="https://doi.org/10.1145/3062341.3062348">doi:10.1145/3062341.3062348</a> <a target="_blank" rel="external noopener" href="https://dblp.org/rec/conf/pldi/ChuWCS17.html">dblp:conf/pldi/ChuWCS17</a> <a target="_blank" rel="external noopener" href="https://fatcat.wiki/release/vbradqk7ovd57ilimbwk5h3piy">fatcat:vbradqk7ovd57ilimbwk5h3piy</a> </span>
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HoTTSQL: proving query rewrites with univalent SQL semantics

Shumo Chu, Konstantin Weitz, Alvin Cheung, Dan Suciu
<span title="2017-06-14">2017</span> <i title="Association for Computing Machinery (ACM)"> <a target="_blank" rel="noopener" href="https://fatcat.wiki/container/xu5bk2lj5rbdxlx6222nw7tsxi" style="color: black;">SIGPLAN notices</a> </i> &nbsp;
In addition, while query equivalence is generally undecidable, we have implemented an automated decision procedure using HoTT SQL for conjunctive queries: a well-studied decidable fragment of SQL that  ...  Part of the challenges comes from the intricacies and rich features of query languages, which makes reasoning about rewrite rules difficult.  ...  HoTT SQL query that projects on the a key of the relation and the index attribute.  ... 
<span class="external-identifiers"> <a target="_blank" rel="external noopener noreferrer" href="https://doi.org/10.1145/3140587.3062348">doi:10.1145/3140587.3062348</a> <a target="_blank" rel="external noopener" href="https://fatcat.wiki/release/ropgf5su6vdvxdterabr7ps74i">fatcat:ropgf5su6vdvxdterabr7ps74i</a> </span>
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Schema merging and mapping creation for relational sources

Rachel Pottinger, Philip A. Bernstein
<span title="">2008</span> <i title="ACM Press"> <a target="_blank" rel="noopener" href="https://fatcat.wiki/container/25kc37fuhndb5axzv75226fwem" style="color: black;">Proceedings of the 11th international conference on Extending database technology Advances in database technology - EDBT &#39;08</a> </i> &nbsp;
We address the problem of generating a mediated schema from a set of relational data source schemas and conjunctive queries that specify where those schemas overlap.  ...  We demonstrate the efficiency of query rewriting in a prototype implementation.  ...  Conjunctive Queries We express mappings over relational schemas as conjunctive queries using Datalog notation, as in Example 3. A database schema is a set of relation schemas.  ... 
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