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In the follow<strong>in</strong>g section we describe how we make use of the catalog data discussed above <strong>in</strong> the generation of HTML<br />

code.<br />

5 Overview of our approach<br />

We use the relationships between database tables which can be found <strong>in</strong> the system catalog of the RDBMS to<br />

automatically build a hypertext from a given database. The result<strong>in</strong>g HTML code can be viewed with a standard web<br />

browser.<br />

Fig. 2: An overview of the web page generation process<br />

[Fig. 2] shows an overview of our approach. We transfer the data from the system catalog to a meta base; ideally, this<br />

data is sufficient for the hypertext generation. However, the user can supply optional additional <strong>in</strong>put <strong>in</strong> a <strong>format</strong><br />

consistent with the catalog data. Additional user <strong>in</strong>put allows for <strong>in</strong>creas<strong>in</strong>g the readability of the result<strong>in</strong>g web pages<br />

and for <strong>in</strong>corporat<strong>in</strong>g additional features <strong>in</strong>to the hypertext as expla<strong>in</strong>ed later.<br />

Our program generator is written <strong>in</strong> the standard Unix record process<strong>in</strong>g language AWK; the programs generated by our<br />

system are <strong>in</strong> AWK as well. We chose this language for our prototype system s<strong>in</strong>ce it is very well suited for this type of<br />

process<strong>in</strong>g, and it is widely available <strong>in</strong> commonly used operat<strong>in</strong>g system and hardware environments. The meta base is<br />

currently implemented <strong>in</strong> MS ACCESS; additional user <strong>in</strong>put is possible via forms. From the meta base we generate a<br />

set of programs. After export<strong>in</strong>g the application data from the database system those programs create correspond<strong>in</strong>g web<br />

pages. L<strong>in</strong>ks to other documents, mean<strong>in</strong>gful section titles and <strong>format</strong>t<strong>in</strong>g commands are added by those programs.<br />

The generated programs are run to produce the web pages from the current application data. A start page is<br />

automatically generated to provide a start<strong>in</strong>g po<strong>in</strong>t for the data exploration. The result<strong>in</strong>g web pages form a three-layer<br />

hierarchy: the start page, the pages for the different entry po<strong>in</strong>ts, and the pages for the data <strong>in</strong>stances.<br />

6 Hypertext Creation<br />

Our hypertext documents are composed of the entries <strong>in</strong> the database and l<strong>in</strong>ks to correspond<strong>in</strong>g other entries. In the

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