发布求助
文献互助 智能选刊 最新文献

Proceedings of the 1st ACM SIGACT-SIGMOD symposium on Principles of database systems最新文献

筛选
英文 中文
Transforming cyclic schemas into trees 将循环模式转换为树
Proceedings of the 1st ACM SIGACT-SIGMOD symposium on Principles of database systems Pub Date : 1982-03-29 DOI: 10.1145/588111.588120
N. Goodman, O. Shmueli
{"title":"Transforming cyclic schemas into trees","authors":"N. Goodman, O. Shmueli","doi":"10.1145/588111.588120","DOIUrl":"https://doi.org/10.1145/588111.588120","url":null,"abstract":"A relational database schema can be thought of as a hypergraph whose nodes are attributes and whose edges are relations. One can partition the class of relational database schemas into tree schemas and cyclic schemas. A schema is a tree schema if there is a tree whose nodes are the schema's relations such that for each attribute, the subtree of nodes containing this attribute is connected. In [BFMMUY El], tree schemas are called acyclic hypergraphs while cyclic schemas are called cyclic hypergraphs.","PeriodicalId":126896,"journal":{"name":"Proceedings of the 1st ACM SIGACT-SIGMOD symposium on Principles of database systems","volume":"99 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133846967","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 25
On concurrency control by multiple versions 关于多版本并发控制
Proceedings of the 1st ACM SIGACT-SIGMOD symposium on Principles of database systems Pub Date : 1982-03-29 DOI: 10.1145/588111.588125
C. Papadimitriou, P. Kanellakis
{"title":"On concurrency control by multiple versions","authors":"C. Papadimitriou, P. Kanellakis","doi":"10.1145/588111.588125","DOIUrl":"https://doi.org/10.1145/588111.588125","url":null,"abstract":"We examine the problem of concurrency control when the database management system supports multiple versions of the data. We characterize the limit of the parallelism achievable by the multiversion approach and demonstrate the resulting space-parallelism tradeoff.","PeriodicalId":126896,"journal":{"name":"Proceedings of the 1st ACM SIGACT-SIGMOD symposium on Principles of database systems","volume":"55 6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114127540","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 3
Horn clauses and the fixpoint query hierarchy Horn子句和固定点查询层次结构
Proceedings of the 1st ACM SIGACT-SIGMOD symposium on Principles of database systems Pub Date : 1982-03-29 DOI: 10.1145/588111.588137
A. K. Chandra, D. Harel
{"title":"Horn clauses and the fixpoint query hierarchy","authors":"A. K. Chandra, D. Harel","doi":"10.1145/588111.588137","DOIUrl":"https://doi.org/10.1145/588111.588137","url":null,"abstract":"A logic program consists of a set of Horn clauses, and can be used to express a query on relational data bases. It is shown that logic programs express precisely the queries in YE+ (the set of queries representable by a fixpoint applied to a positive existential query). Queries expressible by logic programs are thus not first order queries in general; nor are all the first order queries expressible as logic programs. A way of adding the negation operator to logic programs is suggested. The resulting set of clausal queries equals FP, the set of first order queries closed under fixpoints (as well as ¬, ∨, 3).","PeriodicalId":126896,"journal":{"name":"Proceedings of the 1st ACM SIGACT-SIGMOD symposium on Principles of database systems","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125248292","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 49
Database relations with null values 具有空值的数据库关系
Proceedings of the 1st ACM SIGACT-SIGMOD symposium on Principles of database systems Pub Date : 1982-03-29 DOI: 10.1145/588111.588117
C. Zaniolo
{"title":"Database relations with null values","authors":"C. Zaniolo","doi":"10.1145/588111.588117","DOIUrl":"https://doi.org/10.1145/588111.588117","url":null,"abstract":"Permission to copy without fee all or part of this material is granted provided that the copies are not made or distributed for direct commercial advantage, the ACM copyright notice and the title of the p&Ii&on and its date appear, and notice is given that copying is by permission of the Association for Computing Machinery. TO copy otherwise, or to republish, requires a fee and/or specific permission.","PeriodicalId":126896,"journal":{"name":"Proceedings of the 1st ACM SIGACT-SIGMOD symposium on Principles of database systems","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126143843","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 299
Inclusion dependencies and their interaction with functional dependencies 包含依赖项以及它们与功能依赖项的交互
Proceedings of the 1st ACM SIGACT-SIGMOD symposium on Principles of database systems Pub Date : 1982-03-29 DOI: 10.1145/588111.588141
M. Casanova, Ronald Fagin, C. Papadimitriou
{"title":"Inclusion dependencies and their interaction with functional dependencies","authors":"M. Casanova, Ronald Fagin, C. Papadimitriou","doi":"10.1145/588111.588141","DOIUrl":"https://doi.org/10.1145/588111.588141","url":null,"abstract":"Inclusion dependencies, or INDs (which can say, for example, that every manager is an employee) are studied, including their interaction with functional dependencies, or FDs. A simple complete axiomatization for INDs is presented, and the decision problem for INDs is shown to be PSPACE-complete. (The decision problem for INDs is the problem of determining whether or not Σ logically implies σ, given a set Σ of INDs and a single IND σ). It is shown that finite implication (implication over databases with a finite number of tuples) is the same as unrestricted implications for INDs, although finite implication and unrestricted implication are distinct for FDs and INDs taken together. It is shown that, although there are simple complete axiomatizations for FDs alone and for INDs alone, there is no complete axiomatization for FDs and INDs taken together, in which every rule is k-ary for some fixed k (and in particular, there is no finite complete axiomatization.) This is true whether we consider finite implication or unrestricted implication, and is true even if no relation scheme has more than three attributes. The nonexistence of a k-ary complete axiomatization for FDs and INDs taken together is proven by giving a condition which is necessary and sufficient in general for the existence of a k-ary complete axiomatization.","PeriodicalId":126896,"journal":{"name":"Proceedings of the 1st ACM SIGACT-SIGMOD symposium on Principles of database systems","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121848088","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 337
An extended relational algebra with control over duplicate elimination 控制重复消除的扩展关系代数
Proceedings of the 1st ACM SIGACT-SIGMOD symposium on Principles of database systems Pub Date : 1982-03-29 DOI: 10.1145/588111.588132
U. Dayal, N. Goodman, R. Katz
{"title":"An extended relational algebra with control over duplicate elimination","authors":"U. Dayal, N. Goodman, R. Katz","doi":"10.1145/588111.588132","DOIUrl":"https://doi.org/10.1145/588111.588132","url":null,"abstract":"In the pure relational model, duplicate tuples are automatically eliminated. Some real world languages such as DAPLEX, however, give users control over duplicate elimination. This paper extends the relational model to include multiset relations, i.e., relations with duplicate tuples. It considers three formalisms for expressing queries in this model: extended relational algebra, tableaux, and DAPLEX. It shows that, as in the original algebra, the equivalence problem for conjunctive expressions in the extended algebra can be solved using tableaux, and is NP-complete. Finally, it demonstrates that the extended algebra and DAPLEX have essentially the same expressiveness relative to conjunctive expressions.","PeriodicalId":126896,"journal":{"name":"Proceedings of the 1st ACM SIGACT-SIGMOD symposium on Principles of database systems","volume":"106 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132510511","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 97
The inference problem for template dependencies 模板依赖关系的推理问题
Proceedings of the 1st ACM SIGACT-SIGMOD symposium on Principles of database systems Pub Date : 1982-03-29 DOI: 10.1145/588111.588148
Y. Gurevich, H. R. Lewis
{"title":"The inference problem for template dependencies","authors":"Y. Gurevich, H. R. Lewis","doi":"10.1145/588111.588148","DOIUrl":"https://doi.org/10.1145/588111.588148","url":null,"abstract":"A template dependency is a formalized integrity constraint on a relational database, stating that whenever tuples exist in the database that agree on certain attributes, an additional tuple must also be present that agrees with the others in a specified way. It is here shown that the inference problem for template dependencies is undecidable, that is, there can be no algorithm for determining whether a given dependency is a logical consequence of a given finite set of dependencies. The undecidability result holds whether or not databases are considered to be necessarily finite.","PeriodicalId":126896,"journal":{"name":"Proceedings of the 1st ACM SIGACT-SIGMOD symposium on Principles of database systems","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131359054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 35
On equivalences of database schemes 论数据库方案的等价性
Proceedings of the 1st ACM SIGACT-SIGMOD symposium on Principles of database systems Pub Date : 1982-03-29 DOI: 10.1145/588111.588116
J. Rissanen
{"title":"On equivalences of database schemes","authors":"J. Rissanen","doi":"10.1145/588111.588116","DOIUrl":"https://doi.org/10.1145/588111.588116","url":null,"abstract":"One of the fundamental questions in relation theory is the issue of equivalence between two database schemes. In [BMSU] two such schemes were defined to be equivalent when they have the same set of fixed points under the project-join maps associated with the two schemes. This definition requires in an explicit manner the existence of common universal relations, namely the joins, through which the two schemes exchange information, and the resulting “fiipoint” equivalence is a strong one: Both database schemes are in one-to-one correspondence with the subfamily of universal relations, the joins.","PeriodicalId":126896,"journal":{"name":"Proceedings of the 1st ACM SIGACT-SIGMOD symposium on Principles of database systems","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125211145","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 21
Non-reversible privacy transformations 不可逆转的隐私转换
Proceedings of the 1st ACM SIGACT-SIGMOD symposium on Principles of database systems Pub Date : 1982-03-29 DOI: 10.1145/588111.588134
S. Reiss, Mark J. Post, T. Dalenius
{"title":"Non-reversible privacy transformations","authors":"S. Reiss, Mark J. Post, T. Dalenius","doi":"10.1145/588111.588134","DOIUrl":"https://doi.org/10.1145/588111.588134","url":null,"abstract":"This paper discusses techniques for maintaining security in statistical databases. Statistical databases are those from which aggregate information about subsets of the database is to be obtained, as opposed to information concerning individual entities. The problem of security in such databases is one of maintaining individual privacy. Many statistical databases are designed to answer queries concerning groups of individuals. For the system to be totally secure, it must be able to insure that any individual’s information is protected. That is, even if the system is designed to return only group statistics and never individual records, it must be difficult to obtain any individual entry of the database. The degree of difficulty in doing this is a measure of the security of the system. It has been shown that in many statistical database sytems, with enough a priori information it is possible to obtain restricted information concerning an individual (see Schwartz[ 19761, Denning[ 19771, Hoffman[ 19771).","PeriodicalId":126896,"journal":{"name":"Proceedings of the 1st ACM SIGACT-SIGMOD symposium on Principles of database systems","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127764067","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 31
Session details: Session 2 会话详情:会话2
Proceedings of the 1st ACM SIGACT-SIGMOD symposium on Principles of database systems Pub Date : 1982-03-29 DOI: 10.1145/3263949
O. Danvy
{"title":"Session details: Session 2","authors":"O. Danvy","doi":"10.1145/3263949","DOIUrl":"https://doi.org/10.1145/3263949","url":null,"abstract":"","PeriodicalId":126896,"journal":{"name":"Proceedings of the 1st ACM SIGACT-SIGMOD symposium on Principles of database systems","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1982-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131557029","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
首页 上一页 下一页 尾页
0
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整，为了账户安全，请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
现在去查看 取消
×
提示
确定
请完成安全验证×
相关产品
×
本文献相关产品
联系我们：info@booksci.cn Book学术提供免费学术资源搜索服务，方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号：481959085
Book学术官方微信