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Christie, Blair wrote:
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<p class="MsoNormal"><font face="Arial" size="2"><span
style="font-size: 10pt; font-family: Arial;">In the documents this is
dicussed briefly: <o:p></o:p></span></font></p>
<p class="MsoNormal"><font face="Arial" size="2"><span
style="font-size: 10pt; font-family: Arial;">“</span></font><span
lang="EN">). Object models can
often have complex relationships and hierarchies in them - for rules
you will
want to simplify and flatten the model where possible, and let the rule
engine
infer relationships (as it provides future flexibility.”<o:p></o:p></span></p>
<p class="MsoNormal"><font face="Times New Roman" size="3"><span
style="font-size: 12pt;" lang="EN"><o:p> </o:p></span></font></p>
<p class="MsoNormal"><font face="Times New Roman" size="3"><span
style="font-size: 12pt;" lang="EN">What does it mean that the rule
engine can infer
relationships?<o:p></o:p></span></font></p>
<p class="MsoNormal"><font face="Arial" size="2"><span
style="font-size: 10pt; font-family: Arial;">Are there performance
reasons for having a flat model?</span></font></p>
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We can exploit cartesian products and indexing for == constraints. If
its a nested model we have to iterate over all possible instances. The
other problem is if the nested model changes the engine has no idea
this has happened, which if you are not careful can lead to data
integrity issues.<br>
<blockquote
cite="mid:9DA32B4D8579AF44AD96C1CC2E9C518D01DABBBD@MTL-MSG-02.cgiclients.com"
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<p class="MsoNormal"><font face="Arial" size="2"><span
style="font-size: 10pt; font-family: Arial;"> <o:p></o:p></span></font></p>
<p class="MsoNormal"><font face="Arial" size="2"><span
style="font-size: 10pt; font-family: Arial;"><o:p> </o:p></span></font></p>
<p class="MsoNormal"><font face="Arial" size="2"><span
style="font-size: 10pt; font-family: Arial;">Cheers,<br>
<br>
<o:p></o:p></span></font></p>
<p class="MsoNormal"><font face="Arial" size="2"><span
style="font-size: 10pt; font-family: Arial;">Blair </span></font><o:p></o:p></p>
<p class="MsoNormal"><font face="Times New Roman" size="3"><span
style="font-size: 12pt;"><o:p> </o:p></span></font></p>
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