A History-Oriented Temporal SQL Extension

Dozens of temporal extension of the relational data model and of the query language SQL have appeared in recent years. Recently, a committee formed by researchers from the academic and the industrial worlds designed a consensual extension of the SQL-92 standard to include time, epitomized as TSQL2. According to the fundamental concepts of temporal grouping and temporal completeness elaborated by Clifford, Croker and Tuzhilin, TSQL2 and the data model on which it relies (like most of their predecessors) can be shown to be ungrouped and, thus, temporally incomplete. This means that it has been shown that there may exist temporal data models and query languages formally more expressive than TSQL2, and also more easy to use as they would embody a more natural view of objects evolving in time. According to a terminology in use, these temporal languages can also be called history-oriented. The definition of a history-oriented temporal SQL extension is the contribution of this paper. We pre...

• Type: Conference
• Year: 1995
• Where: NGITS
• Authors: Fabio Grandi, Maria Rita Scalas, Paolo Tiberio
• Keywords: Data Models, Information Technology, NGITS 1995, Query Languages, Temporal Extension