It is shown that the concept of interfaces and the concept of composite objects are based on the same mechanism, an instance inheritance relationship. This relationship is integrated into an object-oriented data model which represents interfaces and composite objects in an easy way. The concept of interfaces is generalized to an abstraction mechanism. This allows some severe drawbacks of a rigid interface concept to be eliminated and generic component relationships to be needed.<>
{"title":"Complex and composite objects in CAD/CAM databases","authors":"W. Wilkes, P. Klahold, G. Schlageter","doi":"10.1109/ICDE.1989.47248","DOIUrl":"https://doi.org/10.1109/ICDE.1989.47248","url":null,"abstract":"It is shown that the concept of interfaces and the concept of composite objects are based on the same mechanism, an instance inheritance relationship. This relationship is integrated into an object-oriented data model which represents interfaces and composite objects in an easy way. The concept of interfaces is generalized to an abstraction mechanism. This allows some severe drawbacks of a rigid interface concept to be eliminated and generic component relationships to be needed.<<ETX>>","PeriodicalId":329505,"journal":{"name":"[1989] Proceedings. Fifth International Conference on Data Engineering","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128336373","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}
A database system is considered in which a main-memory database system holds all data in semiconductor memory, and for recovery purposes a backup copy of the database is maintained in secondary storage. The checkpointer is the component of the crash recovery manager responsible for maintaining the backup copy. Ideally, the checkpointer should maintain an almost-up-to-date backup while interfering as little as possible with the system's transaction processing activities. Several algorithms for maintaining such a backup database are presented and compared using an analytic model. The results show some significant performance differences among the algorithms and illustrate some of the tradeoffs that are available in designing such a checkpointer.<>
{"title":"Checkpointing memory-resident databases","authors":"K. Salem, H. Garcia-Molina","doi":"10.1109/ICDE.1989.47249","DOIUrl":"https://doi.org/10.1109/ICDE.1989.47249","url":null,"abstract":"A database system is considered in which a main-memory database system holds all data in semiconductor memory, and for recovery purposes a backup copy of the database is maintained in secondary storage. The checkpointer is the component of the crash recovery manager responsible for maintaining the backup copy. Ideally, the checkpointer should maintain an almost-up-to-date backup while interfering as little as possible with the system's transaction processing activities. Several algorithms for maintaining such a backup database are presented and compared using an analytic model. The results show some significant performance differences among the algorithms and illustrate some of the tradeoffs that are available in designing such a checkpointer.<<ETX>>","PeriodicalId":329505,"journal":{"name":"[1989] Proceedings. Fifth International Conference on Data Engineering","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130206183","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}
The use of set-oriented disk access whereby a variable-sized set of pages can be fetched or flushed to disk in a single call to the I/O system is proposed. This solution provides fast access to variable-length complex objects, yet retains the advantages of a page-structured buffer pool with a conventional frame size. A set-oriented I/O manager has been implemented in the Darmstadt database kernel system using the data-chained I/O method. Performance management indicate considerable enhancement of throughput as well as response time. In the experiments, set-oriented disk access for very large objects performed up to 25 times faster than conventional I/O.<>
{"title":"Set-oriented disk access to large complex objects","authors":"G. Weikum","doi":"10.1109/ICDE.1989.47246","DOIUrl":"https://doi.org/10.1109/ICDE.1989.47246","url":null,"abstract":"The use of set-oriented disk access whereby a variable-sized set of pages can be fetched or flushed to disk in a single call to the I/O system is proposed. This solution provides fast access to variable-length complex objects, yet retains the advantages of a page-structured buffer pool with a conventional frame size. A set-oriented I/O manager has been implemented in the Darmstadt database kernel system using the data-chained I/O method. Performance management indicate considerable enhancement of throughput as well as response time. In the experiments, set-oriented disk access for very large objects performed up to 25 times faster than conventional I/O.<<ETX>>","PeriodicalId":329505,"journal":{"name":"[1989] Proceedings. Fifth International Conference on Data Engineering","volume":"180 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125093820","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}
The Object-Oriented Functional Data Language (O/sup 2/FDL), an interactive, strongly typed database programming language, is discussed. It features inheritance and encapsulation of object-oriented languages and a functional notation for message expressions. The main contributions of the O/sup 2/FDL are: (1) functions of indefinite nesting levels that simplify nested list processing and form the basis of an efficient computation model; (2) path expressions that allow a flexible, graphical correspondence for database queries; (3) a type system featuring parametric and inclusion polymorphism, function restrictions, and type inferencing; and (4) system-defined functions that provide a concise and convenient notation for filtering aggregating, and combining objects. The versatility of the O/sup 2/FDL is demonstrated here for both relationally-complete expressions and more general computations.<>
{"title":"An overview of the Object-Oriented Functional Data Language","authors":"M. Mannino, I. Choi, D. Batory","doi":"10.1109/ICDE.1989.47196","DOIUrl":"https://doi.org/10.1109/ICDE.1989.47196","url":null,"abstract":"The Object-Oriented Functional Data Language (O/sup 2/FDL), an interactive, strongly typed database programming language, is discussed. It features inheritance and encapsulation of object-oriented languages and a functional notation for message expressions. The main contributions of the O/sup 2/FDL are: (1) functions of indefinite nesting levels that simplify nested list processing and form the basis of an efficient computation model; (2) path expressions that allow a flexible, graphical correspondence for database queries; (3) a type system featuring parametric and inclusion polymorphism, function restrictions, and type inferencing; and (4) system-defined functions that provide a concise and convenient notation for filtering aggregating, and combining objects. The versatility of the O/sup 2/FDL is demonstrated here for both relationally-complete expressions and more general computations.<<ETX>>","PeriodicalId":329505,"journal":{"name":"[1989] Proceedings. Fifth International Conference on Data Engineering","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124838474","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}
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.<>
{"title":"Composition of database relations","authors":"R. Agrawal, Shaul Dar, H. Jagadish","doi":"10.1109/ICDE.1989.47205","DOIUrl":"https://doi.org/10.1109/ICDE.1989.47205","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":0.0,"publicationDate":"1989-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134104925","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}
It is shown how intentional answers can be generated as logical consequences of the query and of deduction rules and how integrity constraints can filter out inadequate answers and produce simpler and more informative answers. An efficient organization for the combination of answers and constraints is presented. The authors focus on the design of mechanisms for controlling the generation of intentional answers using integrity constraints. The assertions specified by constraints bear not only on the database but also on queries and intentional answers, since the latter specify sets of values from the database.<>
{"title":"Constraints for improving the generation of intentional answers in a deductive database","authors":"A. Pirotte, Dominique Roelants","doi":"10.1109/ICDE.1989.47273","DOIUrl":"https://doi.org/10.1109/ICDE.1989.47273","url":null,"abstract":"It is shown how intentional answers can be generated as logical consequences of the query and of deduction rules and how integrity constraints can filter out inadequate answers and produce simpler and more informative answers. An efficient organization for the combination of answers and constraints is presented. The authors focus on the design of mechanisms for controlling the generation of intentional answers using integrity constraints. The assertions specified by constraints bear not only on the database but also on queries and intentional answers, since the latter specify sets of values from the database.<<ETX>>","PeriodicalId":329505,"journal":{"name":"[1989] Proceedings. Fifth International Conference on Data Engineering","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131318536","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}
Environments where read-only transactions predominate update transactions are considered. The notion of a group in replicated databases, the recognition of which maximizes the data availability for read-only transactions in error-prone environments, is developed. It is shown that the group identification problem is NP-complete. Replica control algorithms that attempt to approximately determine groups are presented. In one algorithm, groups are determined dynamically; in the other techniques, groups are predefined. It is shown formally that both approaches yield algorithms that preserve the consistency of the database. In the environments considered, the approaches presented are shown to yield significant improvements over other fault-tolerant replica control algorithms.<>
{"title":"Read-only transactions in partitioned replicated databases","authors":"K. Brahmadathan, K. Ramarao","doi":"10.1109/ICDE.1989.47258","DOIUrl":"https://doi.org/10.1109/ICDE.1989.47258","url":null,"abstract":"Environments where read-only transactions predominate update transactions are considered. The notion of a group in replicated databases, the recognition of which maximizes the data availability for read-only transactions in error-prone environments, is developed. It is shown that the group identification problem is NP-complete. Replica control algorithms that attempt to approximately determine groups are presented. In one algorithm, groups are determined dynamically; in the other techniques, groups are predefined. It is shown formally that both approaches yield algorithms that preserve the consistency of the database. In the environments considered, the approaches presented are shown to yield significant improvements over other fault-tolerant replica control algorithms.<<ETX>>","PeriodicalId":329505,"journal":{"name":"[1989] Proceedings. Fifth International Conference on Data Engineering","volume":"65 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131668260","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}
A framework is presented for analysis of time-critical scheduling algorithms. The main assumptions are analyzed behind real-time scheduling and concurrency control algorithms, and a unified approach is proposed. Two main classes of schedulers are identified according to the availability of information about resource requirements and execution times: conflict-resolving schedulers resolve conflicts at run-time, and hence can only produce a sequence of operations satisfying task priorities and resource constraints; and conflict-avoiding schedulers determine resource requirements and expected execution times through offline transaction-class preanalysis and produce a complete time-critical schedule satisfying both timing and resource constraints. For the latter case, the resolution of overload is essential. Examples are given to illustrate the framework and the main classes of scheduling algorithms.<>
{"title":"Time-critical database scheduling: a framework for integrating real-time scheduling and concurrency control","authors":"A. Buchmann, Dennis R. McCarthy, M. Hsu, U. Dayal","doi":"10.1109/ICDE.1989.47251","DOIUrl":"https://doi.org/10.1109/ICDE.1989.47251","url":null,"abstract":"A framework is presented for analysis of time-critical scheduling algorithms. The main assumptions are analyzed behind real-time scheduling and concurrency control algorithms, and a unified approach is proposed. Two main classes of schedulers are identified according to the availability of information about resource requirements and execution times: conflict-resolving schedulers resolve conflicts at run-time, and hence can only produce a sequence of operations satisfying task priorities and resource constraints; and conflict-avoiding schedulers determine resource requirements and expected execution times through offline transaction-class preanalysis and produce a complete time-critical schedule satisfying both timing and resource constraints. For the latter case, the resolution of overload is essential. Examples are given to illustrate the framework and the main classes of scheduling algorithms.<<ETX>>","PeriodicalId":329505,"journal":{"name":"[1989] Proceedings. Fifth International Conference on Data Engineering","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132259255","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}
The concepts of temporal entities and temporal events are distinguished, and the conventional crisp notion of events is extended to define generalized events. Novel definitions are provided for temporal operators used for generalized events. A temporal data model is chosen which is independent of conventional data models, but is similar to temporal data models proposed by other researchers and is sufficiently general to suitable extensions of conventional data models. It is shown how to combine different generalized events and apply temporal operators to such compound events. An outline of a possible implementation of present ideas in the relational data model is provided.<>
{"title":"Generalized events in temporal databases","authors":"S. Dutta","doi":"10.1109/ICDE.1989.47207","DOIUrl":"https://doi.org/10.1109/ICDE.1989.47207","url":null,"abstract":"The concepts of temporal entities and temporal events are distinguished, and the conventional crisp notion of events is extended to define generalized events. Novel definitions are provided for temporal operators used for generalized events. A temporal data model is chosen which is independent of conventional data models, but is similar to temporal data models proposed by other researchers and is sufficiently general to suitable extensions of conventional data models. It is shown how to combine different generalized events and apply temporal operators to such compound events. An outline of a possible implementation of present ideas in the relational data model is provided.<<ETX>>","PeriodicalId":329505,"journal":{"name":"[1989] Proceedings. Fifth International Conference on Data Engineering","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132879272","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}
A global information system (GIS) is an umbrella system that presents a global schema of the data available in its underlying, component, autonomous information systems and provides its users with the capability to ask queries of the global scheme and to receive integrated answers. The major research areas confronting GIS developers are examined. They are: development of global schema; query processing and data access; security; recovery from failure; integration of the user workstation with the GIS; and support for multimedia objects.<>
{"title":"Global information system issues","authors":"I. Kameny","doi":"10.1109/ICDE.1989.47275","DOIUrl":"https://doi.org/10.1109/ICDE.1989.47275","url":null,"abstract":"A global information system (GIS) is an umbrella system that presents a global schema of the data available in its underlying, component, autonomous information systems and provides its users with the capability to ask queries of the global scheme and to receive integrated answers. The major research areas confronting GIS developers are examined. They are: development of global schema; query processing and data access; security; recovery from failure; integration of the user workstation with the GIS; and support for multimedia objects.<<ETX>>","PeriodicalId":329505,"journal":{"name":"[1989] Proceedings. Fifth International Conference on Data Engineering","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1989-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121060438","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}
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