[DDI-SRG] Referencing codes and dimensions

[Wendy Thomas]

The other place this type of reference is used is in category statistics. 
The thing is that since you are talking about a code scheme value as it is 
used in a specific variable you would need (I think) to have a new unique 
ID for each code value within the variable making for a huge amount of 
additional coding (id for each code in the codeScheme plus ID for each 
code in the Variable)....ugh

wendy


On Thu, 17 Jan 2008, Joachim Wackerow wrote:

> Arofan,
>
> Looking at the inline ncube stuff and discussing these issues with Wendy
> I realized the following:
>
> Codes in coding schemes and dimensions in NCubeLogicalProduct are
> referenced not in the usual way. They have no identification but they
> need to be referenced. The reference is indeed made by a combination of
> the identification of an upper level container and a content value at
> the specific element.
>
> I know these are not really new findings. Now I'm wondering if this
> solution is really desirable, to have different methods of referencing.
> At least there seems to be an inconsistency between code and dimension
> (usage of element/attribute). Do we have similar references at other places?
>
> Code
>
> <l:CodeScheme>
>   <l:Identifier>
>     <r:ID>CodeS_2</r:ID>
>   </l:Identifier>
>   <l:CategorySchemeReference>
>     <r:ID>CATS_1</r:ID>
>   </l:CategorySchemeReference>
>   <l:Code>
>     <l:CategoryReference>
>       <r:ID>C_1</r:ID>
>     </l:CategoryReference>
>     <l:Value>1</l:Value>
>   </l:Code>
>
> The steps to find the code 1 would be:
> 1. generate the URN for all Identifier (normalization)
> 2. find CodeScheme with matching URN
> 3. apply XPath expression l:Code[ l:Value = '1' ]
>
> Step 1 and 2 are the common steps to find an Identifier. Step 1 is done
> probably only once for all Identifier, then an index should be provided
> in the application.
> Step 3 is an expensive test on content of an element. This should be
> also done only once to provide an index.
>
>
> Dimension
>
> <l:NCube dimensionCount="3" cellCount="40">
>   <l:Identifier>
>     <r:ID>NCube</r:ID>
>   </l:Identifier>
>   <!-- - - - - - -->
>   <l:Dimension rank="1">
>     <l:VariableReference>
>       <r:ID>V1</r:ID>
>     </l:VariableReference>
>   </l:Dimension>
>
> The steps to find the dimension with rank 1 would be (required by ncube
> modules):
> 1. generate the URN for all Identifier (normalization)
> 2. find NCube with matching URN
> 3. apply XPath expression l:Dimension[ @rank = '1' ]
>
> This is similar as at code but the test is done on the value of an
> attribute.
>
>
> Would it be possible to construct an Identifier for Code and Dimension
> where the ID part is the critical value (Value or @rank) and the rest of
> the URN is inherited by the upper level container (CodeScheme or Ncube).
> This way step 3 would be probably unnecessary and a more consistent way
> of referencing over all would exist.
>
> Achim
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Wendy L. Thomas                          Phone: +1 612.624.4389
Data Access Core Director		 Fax:   +1 612.626.8375
Minnesota Population Center              Email: wlt at pop.umn.edu
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