Title :
A temporal model and query language for ER databases
Author :
Elmasri, Ramez ; Wuu, Gene T J
Author_Institution :
Houston Univ., TX, USA
Abstract :
A temporal extension to an extended ER (entity-relationship) model is proposed. The concept of life span for entities and relationships is incorporated in the ER model. Also specified is a temporal query and update language which is an extension of the GORDAS language. The concepts of temporal Boolean expressions, temporal selection, and temporal projection are introduced, and their use in the query language is illustrated. Temporal constraints are incorporated into the ER model, and the semantics of temporal update operations is defined
Keywords :
database management systems; query languages; ER databases; GORDAS language; entities; entity-relationship; extended ER model; life span; relationships; semantics; temporal Boolean expressions; temporal constraints; temporal extension; temporal model; temporal projection; temporal query language; temporal selection; temporal update language; temporal update operations; Context modeling; Data models; Database languages; Erbium; Relational databases;
Conference_Titel :
Data Engineering, 1990. Proceedings. Sixth International Conference on
Conference_Location :
Los Angeles, CA
Print_ISBN :
0-8186-2025-0
DOI :
10.1109/ICDE.1990.113456
