Survey of XML Query Languages Josh Spiegel

What is an XML Query Language? John Coltrane Maceo Parker Josh Spiegel I want all the employees that make more than $50,000. Roughly like SQL but for XML instead of relational data.

The Languages XQuery Quilt XQL SQL/XML XSL Lorel CXQuery Active XQuery XPath (ANSI/ISO) Almost a W3C recommendation Already the “de facto” standard There are many implementations XML-GL XML-QL Chances are, if you ever end up using an XML query language, you will use XQuery.

Comparative Analysis Comparative Analysis of Five XML Query Languages by Angela Bonifati and Stefano Ceri SIGMOD Record Features an XML Query Language should have Uses the features to compare 5 languages  Lorel  XML-QL  XML-GL  XSL  XQL  ADDED: XQuery

Expectations We expect XQuery to do better than the other 5 languages. The other languages are roughly grandparents of XQuery. XQuery is the “de facto” standard. XQuery will soon be a W3C recommendation.

XQuery could have done better Where it did well  Integration of XML Schema Where it needs improvement  Insert, update, delete  Full support for XPointer and XLink XQuery working group indicates these features will be added in the future. Implementations support features not in the language specification.

Integration of XML Schema XML Schema / DTD define the structure, content and semantics of XML documents e.g. xsd:integer XQuery will never require a XML Schema When a schema is available, more static checks are possible

Integration of XML Schema John Coltrane Maceo Parker Josh Spiegel peanuts Query: What is the average salary?

Integration of XML Schema John Coltrane Maceo Parker Josh Spiegel peanuts Query: What is the average salary?