Efficiently storing and querying XML has been widely studied in research and industrial settings. Major RDBMS vendors now support XML as a native datatype in their systems and provide physical means of storing schema agnostic XML data. Typically this data is stored in CLOBs, BLOBs, or tree forms, with path or value indices used to efficiently process XQuery and SQL queries. However, in many use case queries derived from industrial XML applications, we find that it is very common to query XML based on a group of related property data and to query on the master-detail relationships using the SQL XMLTable construct. We propose an indexing mechanism called the XMLTable Index which is more efficient than the path and value index approach for this class of queries, and provides a way to efficiently process these queries over any physical XML storage form. The XMLTable Index complements the path/value index approach, and can be enhanced in its capabilities by using it in conjunction with path, value, text and other domain indices.

Querying XML effectively and efficiently using declarative languages such as XQuery and XPath has been widely studied in both academic and industrial settings. Most RDBMS vendors now support XML as a native data type with SQL/XML and XQuery support over it. However, the problem of updating XML is still the subject of ongoing effort. Several SQL/XML update extensions have been implemented and an XQuery Update Facility is in the proposal phase to add an update capability to XQuery. There are a lot of challenges involved in updating XML, particularly identifying and updating partial fragments of XML while maintaining concurrency, transactional semantics and validity of the document. In this paper, we illustrate the XML update functionality provided by Oracle XML DB within the context of SQL/XML. This functionality has been developed and optimized based on actual customer use cases of querying and updating XML. We discuss our design philosophy, optimization details for providing capability of updating XML and compare it with the current XQuery Update Facility proposal with the goal of providing insight into incorporating the XQuery Update Facility in the SQL/XML standard in the future.

The interaction with the Web has historically evolved from static bookmarks to dynamic searches to the current usage of active notification mechanisms based on popular protocols like RSS or Atom. In the same time a large volume of important source data is still contained in relational databases. The talk will analyze the way the Oracle database participates to the activation of the data and opening the state changes in a standard and secure way for easy integrating with the rest of the push based Web protocols. We will study the declarative specification of RSS feeds generated based on the state changes detected in the data stored in the Oracle database. On the opposite, external RSS feeds can be injected to the database and processed declaratively in conjunction with the rest of the data. Most of the technical pieces required for such a solution are already supported by the database engine (e.g. declarative XML processing, state change notifications, queues, crawlers, continuous queries), effectively turning the database into a declarative XML hub. The advantages of using database solutions for such problems in an enterprise context are security, scalability and reliability.

XML has become an attractive data processing model for applications. SQL/XML is a SQL standard that integrates XML with SQL. It introduces the XML datatype as a native SQL datatype and defines XML generation functions in the SQL/XML 2003 standard. The goal for the next version of SQL/XML is integrating XQuery with SQL by supporting XQuery embedded inside SQL functions such as the XMLQuery and XMLTable functions. Starting with the 9i database release, Oracle has supported the XML datatype and various operations on XML instances. In this paper, we present the design and implementation strategies of the SQL/XML standard in Oracle XMLDB. We explore the various critical infrastructures needed in the SQL database kernel to support an efficient native XML datatype implementation and the design approaches for efficient generation, query and update of the XML instances. Furthermore, we also illustrate extensions to SQL/XML that makes Oracle XMLDB a truly industrial strength platform for XML processing.

With XQuery becoming the standard language for querying XML, and the relational SQL platform being recognized as an important platform to store and process XML, the SQL/XML standard is integrating XML query capability into the SQL system by introducing new SQL functions and constructs such as XMLQuery() and XMLTable. This paper discusses the Oracle XMLDB XQuery architecture for supporting XQuery in the Oracle ORDBMS kernel which has the XQuery processing tightly integrated with the SQL/XML engine using native XQuery compilation, optimization and execution techniques.

XML is being increasingly used in diverse domains ranging from data and application integration to content management. Oracle provides an enterprise wide platform for managing all types of XML content. Within the Oracle database and the application server, the XML content can be efficiently stored using a variety of storage and indexing methods and it can be processed using multiple standard languages within different programmatic environments. 1.

XML is here as the Internet standard for information exchange among e-businesses and applications. With its dramatic adoption and its ability to model structured, unstructured and semi-structured data, XML has the potential of becoming the data model for Internet data. In recent years, Oracle has evolved its DBMS to support complex, structured, and un-structured data. Oracle has now extended that technology to enable the storage and querying of XML data by evolving its DBMS to an XML enabled DBMS, Oracle8i. We present Oracle's XML-enabling database technology. In particular, we discuss how XML data can be stored, managed and queried in the Oracle8i database.

A relation is an unordered collection of records. Often, however there is an underlying order (e.g., a sequence of stock prices), and users want to pose queries that reflect this order (e.g., find a weekly moving average). SQL provides no support for posing such queries. We show how a rich class of queries reflecting sort order can be naturally expressed and efficiently executed with simple extensions to SQL.