12.2 SQL gateway to databases in Hyper-G

In Hyper-G, as discussed earlier, hypermedia information is stored in the form of objects (text objects, image objects, movie objects, etc.) and the meta-information is represented by collections, clusters and sequence objects (for more details, we refer to Sections 9.2 and 11.1). Beginning in the mid 1980s, most commercial databases started supplying a so-called SQL interface. However, it is quite complicated to develop a generic interface for accessing information via the SQL interface: most commercial vendors unfortunately deviate from the ANSI SQL standard (see Section 12.4); also such a generic interface only provides very limited capabilities.

12.2.1 General considerations

12.2.2 Creating remote SQL objects

12.2.3 An example

12.2.4 SQL interface via CGI

12.2.5 Summary