Abstract

Many Web sites include significant and substantial pieces of information, in a way that is often difficult to share, correlate and maintain. In many cases the management of a Web site can greatly benefit from the adoption of methods and techniques borrowed from the database field. This paper introduces a methodology for designing and maintaining large Web sites based on the assumption that data to be published in the site are managed using a DBMS. We see the process of designing the site as the result of two intertwined activities: the database design and the hypevtex't design. Each of these is further divided in a conceptual design phase and a logical design phase, based on specific data models. A new logical data model, called ADM, is used to describe the structure of a Web hypertext. It is page-oriented, in the sense that the main construct is the one of page-scheme, providing an intensional description of a class of pages in the site. Based on the ADM scheme of the site, we introduce a language, called PENELOPE, that allows to automatically generate HTML pages starting from the database content. PENELOPE is also able to correlate different pages in a complex hypertext using a suitable URL invention mechanism to guarantee reference integrity. ADM and PENELOPE strongly support site maintenance: the first provides a concise description of the site structure; it allows to reason about the overall organization of pages in the site, in order to evaluate the effectiveness and efficiency of the chosen structure, and possibly to restructure it; at the same time, PENELOPE alleviates the burden of managing HTML files by hand, and guarantees link consistency in presence of updates and reorganizations.

Citations