XML represents a fundamental change in computing. It allows applications to move away from proprietary file and data formats to a world of open data interchange. XML has become ubiquitous not only because of its range of applications, but also because of its ease of use. Although XML solves many problems by providing a standard format for data interchange, some challenges remain. In the real world, applications need reliable services to store, retrieve, and manipulate data. These services have traditionally been offered by DB2 for i5/OS. In this IBM Redbooks publication, we discuss the challenges of representing XML hierarchies in the relational database model. We provide an in-depth explanation of the three most popular approaches to bridge the hierarchy, the relational model dichotomy: Programmatically process the XML documents and map their hierarchy into a relational database. Use database middleware to handle the XML parsing and XML-to-relational database mapping. Use Extensible Stylesheet Language (XSL) Transformation to transform inbound XML documents directly to SQL scripts. We also share best practices and techniques aimed at streamlining the XML and DB2 for i5/OS integration. Please note that the additional material referenced in the text is not available from IBM.