Concepts of Bitemporal Database Theory and the Evolution of Web Documents

A vast amount of temporal information is provided on the web. Even though many facts expressed in documents are time-related, the temporal properties of web presentations have not received much attention. In database research, temporal databases have become a mainstream topic in recent years. In web documents temporal data may exist as meta data in the header and as user-directed data in the body of a document. Whereas temporal data can easily be identified in the semi-structured meta data, it is more difficult to determine temporal data and its role in the body. We propose procedures for maintaining temporal integrity of web pages and outline different approaches of applying bitemporal data concepts for web documents. In particular, we regard desirable functionalities of web repositories and other web-related tools that may support the webmasters in managing the temporal data of their web-documents. Some properties of a prototype environment are described.