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An algorithm to compromise the data base, rep. 392
Inform. systems Vol. 5, pp, 239-251 @ Pwt?amn~ Press Ltd., 1960 Printed in Great Britain
REPORTS
AND THESES
T. S. E. Maibaum, C. S. dos Suntos and A. L. F&ado: A Unifo~ Logical Treatment of Queries and Updates, Tech. Rep. DBO~~I-i~0, ~pa~amento de Informa&a, Ponti~cia Universjdade Catolica do Rio de Janeiro, Brash, 1980. Queries and updates on data bases are characterized in a uniform way using a many sorted first-order predicate calculus. The main feature of this characterisation is a formalised notion of data base state. Both updates and queries can be requested trough expressions by the use of predicates supphed in the language of the formal systems. The system would contain a theorem prover which using the axioms defining the date base either synthesizes a valid sequence of update operations (if such exists) or answers the query.
Zbigniew Michalewicz: A Note on Security Problem in I.S.R. Systems, Rep. 385, institute of Computer Science, Polish Academy of Sciences Warsaw, Poland, Jan. 1980. In this paper we propose a formalization of the notion of security in data bases. We define the users’ supplementary knowledge, a disclosure and a data base compromisability. A sufficient condition for compromisability is given in the last part of the paper. Author’s Abstract
lsamu Kobayashi: An Overview of the Database Management Technology, Tech. Rep. TRCS-4, SANNO Institute of Business Administration Kamikasuya, Japan, Dec. 1979.
Authors’ Abstract
Nikolaus Ott: On the Problem of Removing Redundant Join Operations, TR SO.Ol.aO2,Heidelberg Scientific Center, Germany, Jan. 1980. This paper addresses the problem of removing redundant join operations between views which are defined on the same base relation, and it describes a program package to eliminate such joins on the source level of the data base query language. It is shown that certain properties of a given base relation restrict the applicability of the method implemented in these programs. However, performance measurements in a real application of system R prove the usefulness of the method. Author’s Abstruct
Zbigniew Michalewicz: An Algorithm to Compromise the Data Base, Rep. 392, Institute of Computer Science, Polish Academy of Sciences Warsaw, Poland, Jan. l%O. In this paper we consider the problem of compromi~bility of an information system. We propose an algorithm which compromises an information system under certain conditions. We also give a necessary and sufficient condition for compromisability at the end of this paper. Author’s Abstract
Today, databuse is a word in fashion. A number of generalized database management systems are available in the computer society, that can be used as the groundwork of various kinds of information systems. They are placed at the position in the basic programming that is a match for those occupied by programming language translators and operating systems. Too many people want to introduce and use these generalized database management systems, even before they clarify their real needs for these systems. Thus several top sales positions in the software market are usually occupied by some of these generalized database management systems. However, the philosophy that is behind the database technology is not always well understood. Most of database management system users are not aware of what these systems aim at. In consequence, database management systems are very often misused, and unnecessary malpe~ormance is generated. On the other hand, much effort is being devoted to establishing a concrete foundation of database technology. A number of researchers are engaged in developing data models, data processing models, physical database representation, advanced database languages, database machines and so forth. A large part of every conference proceedings and technical journal is usually occupied by related papers. This situation is caused probably because the database technology can be considered as a synthesis of the past computer technology. However, most of these works are too much concentrated in some specific topics and sometimes the significance of these works seems not to be understood even by the authors. Hence these works are not always well consumed by information systems designers. 239
REPORTS
AND THESES
T. S. E. Maibaum, C. S. dos Suntos and A. L. F&ado: A Unifo~ Logical Treatment of Queries and Updates, Tech. Rep. DBO~~I-i~0, ~pa~amento de Informa&a, Ponti~cia Universjdade Catolica do Rio de Janeiro, Brash, 1980. Queries and updates on data bases are characterized in a uniform way using a many sorted first-order predicate calculus. The main feature of this characterisation is a formalised notion of data base state. Both updates and queries can be requested trough expressions by the use of predicates supphed in the language of the formal systems. The system would contain a theorem prover which using the axioms defining the date base either synthesizes a valid sequence of update operations (if such exists) or answers the query.
Zbigniew Michalewicz: A Note on Security Problem in I.S.R. Systems, Rep. 385, institute of Computer Science, Polish Academy of Sciences Warsaw, Poland, Jan. 1980. In this paper we propose a formalization of the notion of security in data bases. We define the users’ supplementary knowledge, a disclosure and a data base compromisability. A sufficient condition for compromisability is given in the last part of the paper. Author’s Abstract
lsamu Kobayashi: An Overview of the Database Management Technology, Tech. Rep. TRCS-4, SANNO Institute of Business Administration Kamikasuya, Japan, Dec. 1979.
Authors’ Abstract
Nikolaus Ott: On the Problem of Removing Redundant Join Operations, TR SO.Ol.aO2,Heidelberg Scientific Center, Germany, Jan. 1980. This paper addresses the problem of removing redundant join operations between views which are defined on the same base relation, and it describes a program package to eliminate such joins on the source level of the data base query language. It is shown that certain properties of a given base relation restrict the applicability of the method implemented in these programs. However, performance measurements in a real application of system R prove the usefulness of the method. Author’s Abstruct
Zbigniew Michalewicz: An Algorithm to Compromise the Data Base, Rep. 392, Institute of Computer Science, Polish Academy of Sciences Warsaw, Poland, Jan. l%O. In this paper we consider the problem of compromi~bility of an information system. We propose an algorithm which compromises an information system under certain conditions. We also give a necessary and sufficient condition for compromisability at the end of this paper. Author’s Abstract
Today, databuse is a word in fashion. A number of generalized database management systems are available in the computer society, that can be used as the groundwork of various kinds of information systems. They are placed at the position in the basic programming that is a match for those occupied by programming language translators and operating systems. Too many people want to introduce and use these generalized database management systems, even before they clarify their real needs for these systems. Thus several top sales positions in the software market are usually occupied by some of these generalized database management systems. However, the philosophy that is behind the database technology is not always well understood. Most of database management system users are not aware of what these systems aim at. In consequence, database management systems are very often misused, and unnecessary malpe~ormance is generated. On the other hand, much effort is being devoted to establishing a concrete foundation of database technology. A number of researchers are engaged in developing data models, data processing models, physical database representation, advanced database languages, database machines and so forth. A large part of every conference proceedings and technical journal is usually occupied by related papers. This situation is caused probably because the database technology can be considered as a synthesis of the past computer technology. However, most of these works are too much concentrated in some specific topics and sometimes the significance of these works seems not to be understood even by the authors. Hence these works are not always well consumed by information systems designers. 239