A Temporal Object-Oriented Data Model with Multiple Granularities

We investigate some issues arising from the introduction of multiple temporal granularities in an object-oriented data model. Although issues concerning temporal granularities have been investigated in the context of temporal relational database systems, no comparable amount of work has been done in the context of object-oriented models. Moreover, the main drawback of the existing proposals is the lack of a formal basis-which we believe is essential to manage the inherent complexity of the object-oriented data model. We provide a complete temporal object-oriented type system supporting multiple temporal granularities and we formally define the set of legal values for our type system. We then address issues related to inheritance, type refinement and substitutability.

Authors

• Isabella Merlo
• Elisa Bertino
• Elena Ferrari 0001
• Giovanna Guerrini

Keywords

• Data models
• Relational databases
• Object oriented modeling
• History
• Read only memory
• Proposals
• Law
• Legal factors
• Electronic switching systems
• Database systems
• Data Model
• Temporal Data
• Temporal Model
• Object-oriented Model
• Multiple Granularities
• Object-oriented Data Model
• Set Of Values
• Legal Value
• Temporal Granularity
• Time Domain
• Set Of Types
• Part Of Function
• Types Of Values
• Time Instants
• Teaching Assistants
• Introductory Course
• Aggregation Function
• Instances Of Type
• Attribute Values
• Finer Granularity
• Theoretical Courses
• User-defined Function