Safety and correct translation of relational calculus formulas
PODS '87 Proceedings of the sixth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems
Time-by-Example Query Language for Historical Databases
IEEE Transactions on Software Engineering
Query processing techniques in the summary-table-by-example database query language
ACM Transactions on Database Systems (TODS)
The Recursive Unsolvability of the Decision Problem for the Class of Definite Formulas
Journal of the ACM (JACM)
Equivalence of Relational Algebra and Relational Calculus Query Languages Having Aggregate Functions
Journal of the ACM (JACM)
Horn clauses and database dependencies
Journal of the ACM (JACM)
On optimizing summary-table-by-example queries
PODS '85 Proceedings of the fourth ACM SIGACT-SIGMOD symposium on Principles of database systems
Principles of Database Systems
Principles of Database Systems
Summary-Table-By-Example: A Database Query Language for Manipulating Summary Data
Proceedings of the First International Conference on Data Engineering
Characterizing Data Base Dependencies
Proceedings of the 8th Colloquium on Automata, Languages and Programming
Mathematical Theory of Computation
Mathematical Theory of Computation
Abe: a query language for constructing aggregates-by-example
SSDBM'81 Proceedings of the 1st LBL Workshop on Statistical database management
Query processing techniques in the summary-table-by-example database query language
ACM Transactions on Database Systems (TODS)
Queries and query processing in object-oriented database systems
ACM Transactions on Information Systems (TOIS)
Towards a unified visual database access
SIGMOD '93 Proceedings of the 1993 ACM SIGMOD international conference on Management of data
Incremental computation of nested relational query expressions
ACM Transactions on Database Systems (TODS)
Providing better support for a class of decision support queries
SIGMOD '96 Proceedings of the 1996 ACM SIGMOD international conference on Management of data
Safety, domain independence and generalized quantification
Data Engineering
Query Processing Techniques for Multimedia Presentations
Multimedia Tools and Applications
Tigukat: a uniform behavioral objectbase management system
The VLDB Journal — The International Journal on Very Large Data Bases - Persistent object systems
Querying Multimedia Presentations Based on Content
IEEE Transactions on Knowledge and Data Engineering
A Graphical Query Language: VISUAL and Its Query Processing
IEEE Transactions on Knowledge and Data Engineering
Database systems for programmable logic controllers
SSDBM'1990 Proceedings of the 5th international conference on Statistical and Scientific Database Management
Efficient implementation of generalized quantification in relational query languages
Proceedings of the VLDB Endowment
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The authors propose a relational calculus (RC/S) which uses set comparison and set manipulation operators to replace universal quantifiers and negations. It is argued that compared to the Codd relational calculus (RC), RC/S queries are easier to construct and comprehend. It is proved that the expressive power of RC is equivalent to the expressive power of RC/S, and algorithms for translating an RC query into an RC/S query and vice versa are given. A safe RC/S query is defined as one that has finite output and can be evaluated in finite time. Then a subset of RC/S queries, called RC/S* is defined, and it is proved that RC/S* is safe. RC/S* is compared to the existing largest safe subsets of RC, i.e. the evaluable formulas and the allowed formulas. Algorithms are given to transform any evaluable formula into an RC/S* query, and some RC/S* formulas that are not evaluable are given. RC/S* queries can be directly implemented using a graphical language similar to Query-by-Example (QBE). Two different graphical languages are described that are equivalent to the RC/S* in expressive power, and these languages are compared to QBE.