• Chapter 1: Getting Started with Stylus Studio®
• Chapter 2: Editing and Querying XML
• Chapter 3: Converting Non-XML Files to XML
• Chapter 4: Working with XSLT
• Chapter 5: Creating XSLT Using the XSLT Mapper
• Chapter 6: Debugging Stylesheets
• Chapter 7: Defining XML Schemas
• Chapter 8: Defining Document Type Definitions
• Chapter 9: Writing XPath Expressions
• Chapter 10: Working with XQuery in Stylus Studio
  • Getting Started with XQuery in Stylus Studio
  • An XQuery Primer
  • Understanding FLWOR Expressions
  • Building an XQuery Using the Mapper
  • Working with the XQuery collection() Function
  • Debugging XQuery Documents
  • Using DataDirect XQuery® Execution Plans
    • Query Plans in Stylus Studio
    • Example of a Query Plan
    • Parts of a Query Plan
    • Displaying a Query Plan
    • Optimizing Your XQuery
  • Creating an XQuery Scenario
  • Generating XQuery Documentation
  • Using XQuery to Invoke a Web Service
  • Using Web Services in XQuery
  • Generating Java Code for XQuery
  • Generating C# Code for XQuery
• Chapter 11: Composing Web Service Calls
• Chapter 12: Working with WSDL Documents
• Chapter 13: Building XML Pipelines
• Chapter 14: Publishing XML Data
• Chapter 15: Integrating with Third-Party File Systems
• Chapter 16: Extending Stylus Studio
• Chapter 17: The Stylus Studio Java API
• Chapter 18: Stylus Studio GUI Reference

Home > Online Product Documentation > Table of Contents > Example of a Query Plan

Example of a Query Plan

The example query plan shown in Figure 331 provides information about how DataDirect XQuery translates the following query, which accesses one relational data source, into a SQL Select statement and how XML results are constructed.

declare option ddtek:plan-explain 'format=xhtml';
               
<myHoldings> {
               
for $holdings in collection("pubs.dbo.holdings")/holdings
               
where $holdings/userid = "Minollo"
               
return <holding
               
quantity="{$holdings/shares}">{$holdings/stockticker/text()}</holding>
               
}
               
</myHoldings>
               

            

In the following query plan, notice how the Relational Data Source node includes details about the SQL Select statement, as well as information about how the result ( $PT) is constructed.

Figure 331. Example of a Query Plan Displayed in the XQuery Editor