Consequences of assuming a universal relation
ACM Transactions on Database Systems (TODS)
The theory of joins in relational databases
ACM Transactions on Database Systems (TODS)
Extending the database relational model to capture more meaning
ACM Transactions on Database Systems (TODS)
Efficient optimization of a class of relational expressions
ACM Transactions on Database Systems (TODS)
Testing implications of data dependencies
ACM Transactions on Database Systems (TODS)
The design and implementation of INGRES
ACM Transactions on Database Systems (TODS)
On the Complexity of Testing Implications of Functional and Join Dependencies
Journal of the ACM (JACM)
Principles of Database Systems
Principles of Database Systems
Can we use the universal instance assumption without using nulls?
SIGMOD '81 Proceedings of the 1981 ACM SIGMOD international conference on Management of data
Assumptions in relational database theory
PODS '82 Proceedings of the 1st ACM SIGACT-SIGMOD symposium on Principles of database systems
Connections in acyclic hypergraphs: extended abstract
PODS '82 Proceedings of the 1st ACM SIGACT-SIGMOD symposium on Principles of database systems
SYSTEM/U: a database system based on the universal relation assumption
ACM Transactions on Database Systems (TODS)
Resolving the query inference problem using Steiner trees
ACM Transactions on Database Systems (TODS)
On the properties and characterization of connection-trap-free schemes
PODS '86 Proceedings of the fifth ACM SIGACT-SIGMOD symposium on Principles of database systems
Update and retrieval in a relational database through a universal schema interface
ACM Transactions on Database Systems (TODS)
NFQL: the natural forms query language
ACM Transactions on Database Systems (TODS)
CSC '89 Proceedings of the 17th conference on ACM Annual Computer Science Conference
Explaining ambiguity in a formal query language
ACM Transactions on Database Systems (TODS)
Pasta-3's graphical query language: direct manipulation cooperative queries, full expressive power
VLDB '89 Proceedings of the 15th international conference on Very large data bases
A transient hypergraph-based model for data access
ACM Transactions on Information Systems (TOIS)
Two-Dimensional Specification of Universal Quantification in a Graphical Database Query Language
IEEE Transactions on Software Engineering
Automatic logical navigation for relational databases
SAC '93 Proceedings of the 1993 ACM/SIGAPP symposium on Applied computing: states of the art and practice
The OODB path-method generator (PMG) using precomputed access relevance
CIKM '93 Proceedings of the second international conference on Information and knowledge management
SIGMOD '95 Proceedings of the 1995 ACM SIGMOD international conference on Management of data
Automated Query Formulation Using an Entity–Relationship Conceptual Schema
Journal of Intelligent Information Systems
A layered architecture for querying dynamic Web content
SIGMOD '99 Proceedings of the 1999 ACM SIGMOD international conference on Management of data
On the foundations of the universal relation model
ACM Transactions on Database Systems (TODS)
On Kent's “Consequences of assuming a universal relation” (Technical correspondance)
ACM Transactions on Database Systems (TODS)
The universal relation revisited (technical correspondence)
ACM Transactions on Database Systems (TODS)
An overview of the multidatabase system MRDSM
ACM '85 Proceedings of the 1985 ACM annual conference on The range of computing : mid-80's perspective: mid-80's perspective
Syntactic Characterization of Tree Database Schemas
Journal of the ACM (JACM)
U2RS: an upgradable universal relation system
CSC '88 Proceedings of the 1988 ACM sixteenth annual conference on Computer science
A universal relation language interface for INGRES
CSC '91 Proceedings of the 19th annual conference on Computer Science
Proceedings of the ninth international conference on Information and knowledge management
SIGMOD '83 Proceedings of the 1983 ACM SIGMOD international conference on Management of data
PODS '83 Proceedings of the 2nd ACM SIGACT-SIGMOD symposium on Principles of database systems
Optimal computation of total projections with unions of simple chase join expressions
SIGMOD '84 Proceedings of the 1984 ACM SIGMOD international conference on Management of data
FLEX: A Tolerant and Cooperative User Interface to Databases
IEEE Transactions on Knowledge and Data Engineering
A Universal Relation Data Model with Semantic Abstractions
IEEE Transactions on Knowledge and Data Engineering
Intensional Answers to Database Queries
IEEE Transactions on Knowledge and Data Engineering
Dynamic Derivation of Personalized Views
VLDB '88 Proceedings of the 14th International Conference on Very Large Data Bases
Universal Relation Views: A Pragmatic Approach
VLDB '83 Proceedings of the 9th International Conference on Very Large Data Bases
The OODB path-method generator (PMG) using access weights and precomputed access relevance
The VLDB Journal — The International Journal on Very Large Data Bases
An abbreviated concept-based query language and its exploratory evaluation
Journal of Systems and Software
A parallel Data Base Machine for query translation in a distributed database system
SAC '86 Proceedings of the 1986 workshop on Applied computing
The case for a wide-table approach to manage sparse relational data sets
Proceedings of the 2007 ACM SIGMOD international conference on Management of data
Join graphs and acyclic database schemes
VLDB '81 Proceedings of the seventh international conference on Very Large Data Bases - Volume 7
Multi-tenant databases for software as a service: schema-mapping techniques
Proceedings of the 2008 ACM SIGMOD international conference on Management of data
Efficient discovery of join plans in schemaless data
IDEAS '09 Proceedings of the 2009 International Database Engineering & Applications Symposium
Proceedings of the 2nd ACM SIGHIT International Health Informatics Symposium
Using trees to mine multirelational databases
Data Mining and Knowledge Discovery
Interestingness measures for association rules within groups
Intelligent Data Analysis
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The universal relation concept is intended to provide the database user with a simplified model in which he can compose queries without regard to the underlying structure of the relations in the database. Frequently, the lossless join criterion provides the query interpreter with the clue needed to interpret the query as the user intended. However, some examples exist where interpretation by the lossless-join rule runs contrary to our intuition. To handle some of these cases, we propose a concept called maximal objects, which modifies the universal relation concept in exactly those situations where it appears to go awry—when the underlying relational structure has “cycles.” We offer examples of how the maximal object concept provides intuitively correct interpretations. We also consider how one might construct maximal objects mechanically from purely syntactic structural information—the relation schemes and functional dependencies—about the database.