{"title":"数据库关系的组成","authors":"R. Agrawal, Shaul Dar, H. Jagadish","doi":"10.1109/ICDE.1989.47205","DOIUrl":null,"url":null,"abstract":"The authors argue for implementing composition as a primitive operation and present a single-sided composition algorithm that performs join protection and duplicate elimination as one unified operation. They report experimental results that show an operating region in which this algorithm outperforms composition by the standard method. This operating region is characterized by a join result many times larger than the source relations, and many duplicates after projection over the nonjoin attributes. This occurs, for example, in deductive databases when computing transitive closures of dense graphs.<<ETX>>","PeriodicalId":329505,"journal":{"name":"[1989] Proceedings. Fifth International Conference on Data Engineering","volume":"25 1","pages":"0"},"PeriodicalIF":0.0000,"publicationDate":"1989-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"8","resultStr":"{\"title\":\"Composition of database relations\",\"authors\":\"R. Agrawal, Shaul Dar, H. Jagadish\",\"doi\":\"10.1109/ICDE.1989.47205\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"The authors argue for implementing composition as a primitive operation and present a single-sided composition algorithm that performs join protection and duplicate elimination as one unified operation. They report experimental results that show an operating region in which this algorithm outperforms composition by the standard method. This operating region is characterized by a join result many times larger than the source relations, and many duplicates after projection over the nonjoin attributes. This occurs, for example, in deductive databases when computing transitive closures of dense graphs.<<ETX>>\",\"PeriodicalId\":329505,\"journal\":{\"name\":\"[1989] Proceedings. Fifth International Conference on Data Engineering\",\"volume\":\"25 1\",\"pages\":\"0\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"1989-02-06\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"8\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"[1989] Proceedings. Fifth International Conference on Data Engineering\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.1109/ICDE.1989.47205\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"[1989] Proceedings. Fifth International Conference on Data Engineering","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1109/ICDE.1989.47205","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
The authors argue for implementing composition as a primitive operation and present a single-sided composition algorithm that performs join protection and duplicate elimination as one unified operation. They report experimental results that show an operating region in which this algorithm outperforms composition by the standard method. This operating region is characterized by a join result many times larger than the source relations, and many duplicates after projection over the nonjoin attributes. This occurs, for example, in deductive databases when computing transitive closures of dense graphs.<>