The expressions stored in a column of a table may contain XPath predicates defined on XMLType attributes. This section describes an application for XPath predicates using the Car4Sale example introduced in Chapter 10 . For this purpose, the information published for each car going on sale includes a Details attribute in addition to the Model , Price , Mileage , and Year attributes. The Details attribute contains additional information about the car in XML format as shown in the following example:
In addition to the core XPath functions defined by the XPath standard, a number of extended functions are also supported with OSM. These extended functions provide additional functionality that is useful to create behaviors, but does not conform to the XPath standard.