{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2023,12,21]],"date-time":"2023-12-21T19:36:27Z","timestamp":1703187387384},"reference-count":19,"publisher":"Elsevier BV","issue":"3","license":[{"start":{"date-parts":[[1984,12,1]],"date-time":"1984-12-01T00:00:00Z","timestamp":470707200000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/www.elsevier.com\/tdm\/userlicense\/1.0\/"},{"start":{"date-parts":[[2013,7,17]],"date-time":"2013-07-17T00:00:00Z","timestamp":1374019200000},"content-version":"vor","delay-in-days":10455,"URL":"https:\/\/www.elsevier.com\/open-access\/userlicense\/1.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Journal of Computer and System Sciences"],"published-print":{"date-parts":[[1984,12]]},"DOI":"10.1016\/0022-0000(84)90004-7","type":"journal-article","created":{"date-parts":[[2003,12,4]],"date-time":"2003-12-04T07:01:00Z","timestamp":1070521260000},"page":"338-358","source":"Crossref","is-referenced-by-count":12,"title":["GYO reductions, canonical connections, tree and cyclic schemas, and tree projections"],"prefix":"10.1016","volume":"29","author":[{"given":"Nathan","family":"Goodman","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Oded","family":"Shmueli","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Y.C.","family":"Tay","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"78","reference":[{"issue":"No. 3","key":"10.1016\/0022-0000(84)90004-7_BIB1","doi-asserted-by":"crossref","first-page":"297","DOI":"10.1145\/320083.320091","article-title":"The theory of joins in relational databases","volume":"4","author":"Aho","year":"1979","journal-title":"ACM Trans. Database Systems"},{"issue":"No. 2","key":"10.1016\/0022-0000(84)90004-7_BIB2","doi-asserted-by":"crossref","first-page":"218","DOI":"10.1137\/0208017","article-title":"Equivalence among relational expressions","volume":"8","author":"Aho","year":"1979","journal-title":"SIAM J. Comput."},{"key":"10.1016\/0022-0000(84)90004-7_BIB3","series-title":"Proc. ACM Symposium on Theory of Computation","first-page":"353","article-title":"Properties of acyclic database schemes","author":"Beeri","year":"1981"},{"issue":"No. 3","key":"10.1016\/0022-0000(84)90004-7_BIB4","doi-asserted-by":"crossref","first-page":"479","DOI":"10.1145\/2402.322389","article-title":"On the desirability of acyclic database schemes","volume":"30","author":"Beeri","year":"1983","journal-title":"J. Assoc. Comput. Mach."},{"issue":"No. 1","key":"10.1016\/0022-0000(84)90004-7_BIB5","doi-asserted-by":"crossref","first-page":"25","DOI":"10.1145\/322234.322238","article-title":"Using semijoins to solve relational queries","volume":"28","author":"Bernstein","year":"1981","journal-title":"J. Assoc. Comput. Mach."},{"issue":"No. 4","key":"10.1016\/0022-0000(84)90004-7_BIB6","doi-asserted-by":"crossref","first-page":"751","DOI":"10.1137\/0210059","article-title":"The power of natural semijoins","volume":"10","author":"Bernstein","year":"1981","journal-title":"SIAM J. Comput."},{"issue":"No. 3","key":"10.1016\/0022-0000(84)90004-7_BIB7","doi-asserted-by":"crossref","first-page":"514","DOI":"10.1145\/2402.322390","article-title":"Types of acyclicity for hypergraphs and relational database systems","volume":"30","author":"Fagin","year":"1983","journal-title":"J. Assoc. Comput. Mach."},{"issue":"No. 3","key":"10.1016\/0022-0000(84)90004-7_BIB8","doi-asserted-by":"crossref","first-page":"343","DOI":"10.1145\/319732.319735","article-title":"A simplified universal relation assumption and its properties","volume":"7","author":"Fagin","year":"1982","journal-title":"ACM Trans. Database Systems"},{"key":"10.1016\/0022-0000(84)90004-7_BIB9","series-title":"Computers and Intractability: A Guide to the Theory of NP-Completeness","author":"Garey","year":"1979"},{"key":"10.1016\/0022-0000(84)90004-7_BIB10","article-title":"On the Universal Relation","author":"Graham","year":"1979"},{"issue":"No. 4","key":"10.1016\/0022-0000(84)90004-7_BIB11","doi-asserted-by":"crossref","first-page":"653","DOI":"10.1145\/319758.319775","article-title":"Tree queries: A simple class of relational queries","volume":"7","author":"Goodman","year":"1982","journal-title":"ACM Trans. Database Systems"},{"issue":"No. 4","key":"10.1016\/0022-0000(84)90004-7_BIB12","doi-asserted-by":"crossref","first-page":"767","DOI":"10.1145\/2157.322405","article-title":"Syntactic characterizations of database schemas","volume":"30","author":"Goodman","year":"1983","journal-title":"J. Assoc. Comput. Mach."},{"issue":"No. 1","key":"10.1016\/0022-0000(84)90004-7_BIB13","doi-asserted-by":"crossref","first-page":"60","DOI":"10.1016\/0022-0000(84)90076-X","article-title":"The tree projection theorem and relational query processing","volume":"28","author":"Goodman","year":"1984","journal-title":"J. Comput. System Sci."},{"key":"10.1016\/0022-0000(84)90004-7_BIB14","series-title":"Proc. ACM SIGACT-SIGMOD Conference on Principles of Database Systems","first-page":"49","article-title":"Transforming cyclic schemas into trees","author":"Goodman","year":"1982"},{"issue":"No. 3","key":"10.1016\/0022-0000(84)90004-7_BIB15","doi-asserted-by":"crossref","first-page":"331","DOI":"10.1016\/0022-0000(83)90046-6","article-title":"Acyclic join dependencies and database projections","volume":"27","author":"Hull","year":"1983","journal-title":"J. Comput. System Sci."},{"key":"10.1016\/0022-0000(84)90004-7_BIB16","series-title":"Proc. ACM SIGACT-SIGMOD Conference on Principles of Database Systems","first-page":"34","article-title":"Connections in acyclic hypergraphs","author":"Maier","year":"1981"},{"key":"10.1016\/0022-0000(84)90004-7_BIB17","series-title":"Proc. Symposium on Mathematical Foundations of Computer Science No. 64","first-page":"537","article-title":"Theory of joins for relational databases\u2014a tutorial survey","author":"Rissanen","year":"1978"},{"key":"10.1016\/0022-0000(84)90004-7_BIB18","series-title":"Proc VLDB","first-page":"82","article-title":"Algorithms for acyclic database schemes","author":"Yannakakis","year":"1981"},{"key":"10.1016\/0022-0000(84)90004-7_BIB19","series-title":"Proc. IEEE COMPSAC","article-title":"An algorithm for tree-query membership of a distributed query","author":"Yu","year":"1979"}],"container-title":["Journal of Computer and System Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.elsevier.com\/content\/article\/PII:0022000084900047?httpAccept=text\/xml","content-type":"text\/xml","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/api.elsevier.com\/content\/article\/PII:0022000084900047?httpAccept=text\/plain","content-type":"text\/plain","content-version":"vor","intended-application":"text-mining"}],"deposited":{"date-parts":[[2019,2,16]],"date-time":"2019-02-16T08:51:58Z","timestamp":1550307118000},"score":1,"resource":{"primary":{"URL":"https:\/\/linkinghub.elsevier.com\/retrieve\/pii\/0022000084900047"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1984,12]]},"references-count":19,"journal-issue":{"issue":"3","published-print":{"date-parts":[[1984,12]]}},"alternative-id":["0022000084900047"],"URL":"https:\/\/doi.org\/10.1016\/0022-0000(84)90004-7","relation":{},"ISSN":["0022-0000"],"issn-type":[{"value":"0022-0000","type":"print"}],"subject":[],"published":{"date-parts":[[1984,12]]}}}