Ajay Vohra

XML is increasingly being used as the language of data exchange. An XML document based on a DTD or a XML Schema contains data that conforms to a standard structure. A number of technologies, such as ebXML (Electronic Business XML), UDDI (Universal Description, Discovery, and Integration), and RDF (Resource Description Framework) are based on XML. New business concepts, such as B2C and B2B, e-services, commerce resource platform, peer-to-peer commerce and collaborative commerce, have emerged as a result of XML. In this article, XML data management in Adaptive Server Enterprise 12.5 is highlighted.

Overview
XML data management in Sybase Adaptive Server Enterprise is implemented with the XML Management Package. This tutorial will cover the database’s role in XML data management, ASE 12.5 data management support, and XML processing in ASE 12.5. We’ll start with the role of a database in XML data management.

Database’s Role in XML Data Management
Most XML processing without a database is done in the application layer. XML processing in the application layer has its disadvantages. Parsing XML in the application layer doesn’t include storing and querying the parsed XML document. Querying XML data with XPath and XQuery with a query engine isn’t supported. Transforming data with a XSLT processor and storing data in a file system is less optimal than database-based transformation and storage.

A database may be used for storing and indexing XML data, querying XML data, and mapping and transforming XML data.

XML Storage and Indexing
An XML document may be parsed and the data in the document may be stored in a relational database. The most optimal way of storing an XML document is in a database that supports integrated XML data management. A database integrated with XML data management provides methods for storing, indexing, and querying XML data.

XML Query
A database user may want to query a database for XML data stored in a database. A database query can span multiple XML documents. A database integrated with XML data management provides a query engine for querying XML data based on SQL/XML, XQuery, and XPath.

XML Mapping and Transformation
XML data stored in a database may have to be transformed into another format. A database integrated with XML data management supports the transformation of SQL/XML data.

ASE 12.5 XML Data Management Support
Adaptive Server Enterprise 12.5 supports XML storage, XML indexing, XML querying, and XML mapping and transformation. XML data management in Adaptive Server Enterprise is implemented with the XML Management Package.

XML Storage and Indexing
ASE 12.5 integrates XML data management with the RDBMS. Optimal methods are used for storing, indexing, and querying XML data instead of the RDBMS-based storing, indexing, and querying methods. XML data is stored like SQL data. Indexing XML elements, attributes, and paths is supported.

XML Query
ASE query engines support querying data based on SQL/XML (SQLX), XPath, and XQuery. ASE provides for the complete interchangeability of SQL-XML data. SQL operations can be done on XML data and XML operations can be done on SQL data.

XML Mapping and Transformation
ASE supports XML mapping and transformation. With Transact SQL, XML output can be produced from data in an RDBMS. ASE supports SQLX, XPath, and Xquery, which may be required in data transformation. An XSLT engine can be deployed in ASE to transform the data. SQL and XML data can be transformed into another format.