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Home -> Community -> Usenet -> comp.databases.theory -> Re: vehicle to autoparts relationships
NENASHI, Tegiri wrote:
> "Aloha Kakuikanu" <aloha.kakuikanu_at_yahoo.com> wrote in
> news:1164244417.310045.85570_at_e3g2000cwe.googlegroups.com:
> > NENASHI, Tegiri wrote:
> >> You want to say the set containment join, is not it ? If you do,
> >> there are two problems: 1) the performance of set containment join;
> >> 2) the set valued attribute, or relation valued attribute, is not
> >> realised by all the databases. One can have a separate relation in
> >> the place of the relation valued attribute, of course, but then how
> >> does one reference the relation from AssemblyParts with
> >> assemblyPartNo ?
> >
> > No nested relations.
>
> Then how you create the schema ? Please show with tables: what is it
> that assemblyPartNo references ?
(referred to the rifle diagramm example above)
table Parts:
part# partName
------ ------------- 100 - BARREL 102 - BARREL NUT 104 - BARREL EXTENSION 108 - BARREL RETAINER 110 - BOLT 112 - EXTRACTOR 114 - EXTRACTOR AXIS 116 - EJECTOR
table AssemblyParts:
assemblyPart# part# partName
----------------- ----- ------------- 1 112 EXTRACTOR ASSEMBLY 1 114 EXTRACTOR ASSEMBLY 1 194 EXTRACTOR ASSEMBLY 1 112 BOLT ASSEMBLY 1 114 BOLT ASSEMBLY 1 194 BOLT ASSEMBLY 1 110 BOLT ASSEMBLY 1 116 BOLT ASSEMBLY
In this particular example we see that
{112,114,194} <= {112,114,194,110,116}
in other words, BOLT ASSEMBLY includes EXTRACTOR ASSEMBLY. Received on Wed Nov 22 2006 - 19:50:19 CST
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