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<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>The operator tree is an internal representation (left to the
implementation-internals) of the logical and/or physical operations that are
used to execute the query expression. Similar to the operators you see in other
language compilation examples (be it byte codes, or relational operators inside
a database).<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Best regards<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'>Michael<o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";
color:#1F497D'><o:p> </o:p></span></p>
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<p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span
style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>
talk-bounces@x-query.com [mailto:talk-bounces@x-query.com] <b>On Behalf Of </b>Roger
Holmes<br>
<b>Sent:</b> Tuesday, March 24, 2009 10:22 AM<br>
<b>To:</b> talk@x-query.com<br>
<b>Subject:</b> [xquery-talk] Help Understanding the XQJ Model<o:p></o:p></span></p>
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<p class=MsoNormal><o:p> </o:p></p>
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<p class=MsoNormal>Hi,<o:p></o:p></p>
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<p class=MsoNormal>I was wondering how do the Data Model instances (XDM,
infoset, DOM) also known as trees (listed as DM4 in the XQJ Specification
diagram "Processing Model overview") differ from the
"Operation Tree" (identified as SQ5) and how do they interact ?<o:p></o:p></p>
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<p class=MsoNormal> <o:p></o:p></p>
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<p class=MsoNormal>I am right in thinking the operation tree is purely
instructional albeit with information resolved from the context whereas
the data model contains actual data ?<o:p></o:p></p>
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<p class=MsoNormal> <o:p></o:p></p>
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<p class=MsoNormal>How have the operation trees differed across Xquery
implementations ? Do they relate at all to the classic Binary Search
Tree (i.e go either left or right) ?<o:p></o:p></p>
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<p class=MsoNormal> <o:p></o:p></p>
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<p class=MsoNormal> <o:p></o:p></p>
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<p class=MsoNormal>Thanks,<o:p></o:p></p>
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<p class=MsoNormal>Roger<o:p></o:p></p>
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<p class=MsoNormal><o:p> </o:p></p>
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