Smalltalk-80: the language and its implementation
Smalltalk-80: the language and its implementation
An introduction to database systems: vol. I (4th ed.)
An introduction to database systems: vol. I (4th ed.)
A shared, segmented memory system for an object-oriented database
ACM Transactions on Information Systems (TOIS)
Data model issues for object-oriented applications
ACM Transactions on Information Systems (TOIS)
Development and implementation of an object-oriented DBMS
Research directions in object-oriented programming
A query model and an object algebra for object-oriented databases
A query model and an object algebra for object-oriented databases
The architecture of the EXODUS extensible DBMS
OODS '86 Proceedings on the 1986 international workshop on Object-oriented database systems
The design and implementation of INGRES
ACM Transactions on Database Systems (TODS)
IEEE Transactions on Knowledge and Data Engineering
Incremental view maintenance in object-oriented databases
ACM SIGMIS Database
Maximizing reusability: seeking appropriate positions for derived classes within the class hierarchy
SAC '00 Proceedings of the 2000 ACM symposium on Applied computing - Volume 1
Proceedings of the 2001 ACM symposium on Applied computing
Documenting Legacy Relational Databases
ER '99 Proceedings of the Workshops on Evolution and Change in Data Management, Reverse Engineering in Information Systems, and the World Wide Web and Conceptual Modeling
A Model for Deferred View Maintenance
IDEAS '99 Proceedings of the 1999 International Symposium on Database Engineering & Applications
Views as first-class citizens in object-oriented databases
The VLDB Journal — The International Journal on Very Large Data Bases
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An object-algebra is presented as a formal query model for object-oriented data models. The algebra serves not only to access and manipulate the structure and behavior of objects, but it also supports the creation of new objects and the introduction of new relationships into the schema. It provides a more powerful and flexible tool than messages for effectively dealing with complex situations and meeting associative access requirements. Operands as well as the results of operations in the proposed algebra are formally characterized as a pair of sets—a set of objects capturing the states and a set of message expressions comprised of sequences of messages modeling the object behavior. The closure property is achieved in a natural way by letting the results of operations possess the same characteristics as the operands in an algebra expression. Some operators of the algebra resemble those of the relational algebra but with different syntax and semantics. Additional operators are introduced to complement them. A class is shown to posses the properties of an operand by defining a set of objects and deriving a set of message expressions for it. Furthermore, the result of an object algebra expression is shown to have the characteristics of a class whose superclass/subclass relationships with its operand class(es) can be established providing a mechanism to properly and persistently place it in the class lattice (schema).