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 data model and query language for EXODUS
SIGMOD '88 Proceedings of the 1988 ACM SIGMOD international conference on Management of data
Identity, equality and query optimization
Lecture notes in computer science on Advances in object-oriented database systems
Data abstraction and query optimization
Lecture notes in computer science on Advances in object-oriented database systems
A recursive algebra and query optimization for nested relations
SIGMOD '89 Proceedings of the 1989 ACM SIGMOD international conference on Management of data
A model of queries for object-oriented databases
VLDB '89 Proceedings of the 15th international conference on Very large data bases
OQL: a query language for manipulating object-oriented databases
VLDB '89 Proceedings of the 15th international conference on Very large data bases
Queries and views in an object-oriented data model
Proceedings of the second international workshop on Database programming languages
Queries and query processing in object-oriented database systems
ACM Transactions on Information Systems (TOIS)
A general framework for the optimization of object-oriented queries
SIGMOD '92 Proceedings of the 1992 ACM SIGMOD international conference on Management of data
A query model and an object algebra for object-oriented databases
A query model and an object algebra for object-oriented databases
PDM: an object-oriented data model
OODS '86 Proceedings on the 1986 international workshop on Object-oriented database systems
Remarks on the algebra of non first normal form relations
PODS '82 Proceedings of the 1st ACM SIGACT-SIGMOD symposium on Principles of database systems
Object-Oriented Databases: Definition and Research Directions
IEEE Transactions on Knowledge and Data Engineering
Queries in Object-Oriented Databases
Proceedings of the Fourth International Conference on Data Engineering
A Query Algebra for Object-Oriented Databases
Proceedings of the Sixth International Conference on Data Engineering
Cloud algebra for cloud database management system
Proceedings of the Second International Conference on Computational Science, Engineering and Information Technology
Hi-index | 0.00 |
Although messages can be used to manipulate objects, a query language is still considered a required component of object-oriented database management systems. An object algebra is proposed, as a formal foundation for a query language, that can handle both the state and the behavior of objects. Creation of new objects and introduction of new relationships among objects/classes are also facilitated by the object algebra. The object algebra subsumes the five basic relational algebraic operations while providing several additional powerful ones. Each operand, as well as the result of a query, is a pair of sets: a set of objects and a set of message expressions formed as a sequence of messages accepted by the former set. The result of a query possesses the properties of an operand, thus providing the closure property for operations. Every class has a defined set of objects and derived set of message expressions, thus a class possesses the characteristics of an operand. The result of a query also possesses the characteristics of a class. The superclass/subclass relationships of a query result with the operands is established to provide persistency to the result as a class, and as a consequence algebraic equivalents of schema evolution functions are developed. Object algebra is as powerful as relational and nested relational algebra. In fact, due to message expressions that serve to handle both stored and derived values, object algebra provides greater computational power.