[xquery-talk] Time complexity of XQuery

[Amitabh Ojha]

Dear members,

I  invite your attention to the following  XML document, data.xml :

<?xml version="1.0"?>
<KMeansData>

  <Object>
    <X>41</X>
    <Y>3</Y>
  </Object>

  <Object>
    <X>65</X>
    <Y>16</Y>
  </Object>

  <Object>
    <X>10</X>
    <Y>20</Y>
  </Object>

</KMeansData>

Also, pl see the following query :

let $x := doc (“data.xml”)/KMeansData/Object
for $y  in  $x
return ($y/X,  $y/Y)


If  “n”  be the  number  of  elements  named “Object” in the XML file above,  then  would  the  time complexity of the XQuery above be      O(n)  or  O(n^2) ?   

I am asking this question  because while using a particular XQuery Engine,  I did an experiment  with synthetically  generated  XML data for  upto n = 10,000.  While the time remained O (n) i.e linear upto n = 7,000 but after that,  I noticed a tendency towards O(n^2).

Will appreciate your comments/ help.

Amitabh Ojha



  
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