The design and implementation of INGRES
ACM Transactions on Database Systems (TODS)
A relational model of data for large shared data banks
Communications of the ACM
Specifying connections for a universal relation scheme database
SIGMOD '82 Proceedings of the 1982 ACM SIGMOD international conference on Management of data
The universal instance and database design
The universal instance and database design
Resolving the query inference problem using Steiner trees
ACM Transactions on Database Systems (TODS)
Dynamic query interpretation in relational databases
PODS '87 Proceedings of the sixth ACM SIGACT-SIGMOD-SIGART symposium on Principles of database systems
Explaining ambiguity in a formal query language
ACM Transactions on Database Systems (TODS)
Early Experience with the Visual Programmer's WorkBench
IEEE Transactions on Software Engineering
Database states and their tableaux
ACM Transactions on Database Systems (TODS)
On the foundations of the universal relation model
ACM Transactions on Database Systems (TODS)
A high-level user interface for update and retrieval in relational databases—language aspects
SIGMOD '85 Proceedings of the 1985 ACM SIGMOD international conference on Management of data
On Kent's “Consequences of assuming a universal relation” (Technical correspondance)
ACM Transactions on Database Systems (TODS)
U2RS: an upgradable universal relation system
CSC '88 Proceedings of the 1988 ACM sixteenth annual conference on Computer science
SIGMOD '83 Proceedings of the 1983 ACM SIGMOD international conference on Management of data
Specifying connections for a universal relation scheme database
SIGMOD '82 Proceedings of the 1982 ACM SIGMOD international conference on Management of data
Inclusion dependencies and the universal instance
PODS '83 Proceedings of the 2nd ACM SIGACT-SIGMOD symposium on Principles of database systems
PODS '83 Proceedings of the 2nd ACM SIGACT-SIGMOD symposium on Principles of database systems
Intensional Answers to Database Queries
IEEE Transactions on Knowledge and Data Engineering
Universal Relation Views: A Pragmatic Approach
VLDB '83 Proceedings of the 9th International Conference on Very Large Data Bases
A survey of approaches to automatic schema matching
The VLDB Journal — The International Journal on Very Large Data Bases
A Data Model for Data Integration
Electronic Notes in Theoretical Computer Science (ENTCS)
Logical data independence reconsidered (extended abstract)
ISMIS'05 Proceedings of the 15th international conference on Foundations of Intelligent Systems
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One of the main goals of database systems, relational systems in particular, is to provide a degree of physical data independence for users and programs. Users should not need to know the exact physical storage structures to use the database, and should be protected from changes in those structures. We attempt to go a step further, to logical data independence. We want an interface to a relational database where a user need not be concerned with how the data has been partitioned into various relations. The natural relation schemes to be used, from a semantic point of view, may be decomposed in the database for normalization or redundancy reasons. Our approach essentially loads all the semantics onto the attributes. In our query language tuple variables are not bound to specific relations. Rather, the system uses the set of attributes, say X, that appear in a query with a tuple variable, say t, to combine the database relations to form a single relation with scheme X over which t ranges. We describe our method for constructing such a relation given the associated set of attributes X. When tuple variables are bound implicitly, the logical connectives 'and', 'or', and 'not' take on 'semantic overtones' since they can affect the binding. We discuss the motivation behind the chosen semantics for these connectives. Our goal is a powerful, yet concise, query language with natural semantics.