On Thu, May 24, 2007 at 05:07:03PM +0200, Maarten Clements wrote:
> Using the following XQuery in MonetDb (WinXP) crashes on large documents

the usual questions:

1) which version of MonetDB XQuery are you using?
2) what exactly does "crash" mean?
   does the Mserver simply stop? Is the any error message? Does Mserver
   grow/excessively use resources before crashing? ...?
3) what does "large" and "small" mean wrt., your document sizes?
   (serialized file size in byte? number of /collection/doc nodes in either
    document? ...?)
4) how much memory does your machine have?
 
> (when C1 and C2 are small it works ok):
>  
> >  <col> { 
> >    for $b in doc("C1.xml")/collection/doc 
> >    for $top in doc("C2.xml")/collection/doc
> >    where ($b/year > 1950) and ($b/title = $top/title)
> >    return 
> >      <movie>
> >        {$b/year}
> >      </movie>
> >  } </col>
> 
> If I remove one of the two conditions it works perfectly, e.g.:
>  
> >  <col> { 
> >    for $b in doc("C1.xml")/collection/doc 
> >    for $top in doc("C2.xml")/collection/doc
> >    where ($b/title = $top/title)
> >    return 
> >      <movie>
> >        {$b/year}
> >      </movie>
> >  } </col>
> 
> Can anyone explain this problem?

most probably, the more complex join condition is not recognized as join,
then the intermediate result (corss product) blows up.

Stefan

>  
> 
> ______________________________
> Maarten Clements
> 
> 
> 
>  

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