Re: vehicle to autoparts relationships
From: Bob Badour <bbadour_at_pei.sympatico.ca>
Date: Thu, 07 Dec 2006 18:06:19 GMT
Message-ID: <vKYdh.29784$cz.448021_at_ursa-nb00s0.nbnet.nb.ca>
>
> And the third alternative is to use sets (where atomic parts are
> elements, and the part assemblies are sets). No recursion is needed
> then! The ancestor chain query is a relational division, but in a
> typical autoparts shop application, why would one like to know what
> chain of assemblies includes an atomic part?
>
> BTW, it seems like your replies progressed from crankish to
> knowledgeable -- congratulations! Gonna miss your db4d stuff. Well,
> maybe not:-)
Date: Thu, 07 Dec 2006 18:06:19 GMT
Message-ID: <vKYdh.29784$cz.448021_at_ursa-nb00s0.nbnet.nb.ca>
Aloha Kakuikanu wrote:
> Neo wrote:
>
>>At extremes, there are two type of solutions to your problem in RMDBs. >>One solutions ends up with many specialized tables. The other solution >>ends up with fewer generalized tables with recursive joins. Each has >>advantages and disadvantages. You will have to find the right balance >>for your specific requirements.
>
> And the third alternative is to use sets (where atomic parts are
> elements, and the part assemblies are sets). No recursion is needed
> then! The ancestor chain query is a relational division, but in a
> typical autoparts shop application, why would one like to know what
> chain of assemblies includes an atomic part?
>
> BTW, it seems like your replies progressed from crankish to
> knowledgeable -- congratulations! Gonna miss your db4d stuff. Well,
> maybe not:-)
Like hell they did. Received on Thu Dec 07 2006 - 19:06:19 CET