Optimizing XPath Queries

Two of XML's biggest strengths are its abilities to represent arbitrary types of data (e.g., purchase orders, financial transactions, calendar items) and to provide a platform-neutral format for exchanging data between business partners. Once you've decided to exchange XML data with your business partner, you need to agree on the XML grammar you'll use to exchange the data. You'll either invent your own custom XML grammar or adopt a predefined, industry-standard grammar such as the XML Common Business Library, xCBL (see http://www.xcbl.org for details about xCBL), if one is relevant to your application. In most cases, you'll build or obtain the XML Schema Definition (XSD) schema that defines the grammar you've created or selected. Although it's not a strict requirement, a schema provides a formal agreement between you and your business partner on the format of the exchanged data.

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