9.4. Detailed Design Descriptions

In this section we explore three aspects of the prototype in some detail: the object-relational DBMS schema used to hold the XML document schemas and data, the user-defined types needed to make hierarchical operations efficient, and the algorithms used to map XPath expressions to their corresponding SQL-3 queries.

Figure 9.3 presents the basic schema used in the prototype in an entity-relationship diagram, and Listing 9.3 shows the required SQL-3 DDL (Data Definition Language). What Figure 9.3 conveys can be thought of as a design pattern, rather than a complete schema. Because the prototype generates all of its SQL at runtime, it has considerable flexibility in terms of how it uses the table and schema management ...

Get XML Data Management: Native XML and XML-Enabled Database Systems now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.