[DDI-SRG] TIC Meeting: Identifier issues

[Chris Nelson]

Pascal,
That's fine, as long as applications know what to do.  But I guess if the
URN is used it will have to be the full URN.

Chris
-----Original Message-----
From: Pascal Heus [mailto:pascal.heus at gmail.com] 
Sent: 30 October 2007 12:07
To: Chris Nelson
Cc: 'Joachim Wackerow'; 'DDI Technical Implementation Committee'; 'Chris
Nelson'
Subject: Re: [DDI-SRG] TIC Meeting: Identifier issues

Chris:
Thanks for your input. Regrading your note on mandatory ID in reference 
of the enclosing maintainable object (for versionable and identifiable), 
this is really something we want o avoid in DDI as it will lead to 
hundred of repeat of the same element. To alleviate this problem, we 
have introduced the "default" scheme mechanism. For example, in the 
PhysicalDataProduct RecordLayout, a defaultVariableScheme is defined and 
use for all the variable reference in the layout. Otherwise, I will 
repeat the same infomration for every variable which can repeat hundred 
or thousands of time. This element already exists in references as the 
optional 'scheme'. I agree that it can be present but should not be 
mandatory (unless a default is not provided, this should be validate by 
the DDI Parser).

Achim:
a few more questions:
- what is the @action attribute in identifiers?
- In your email, you mention that Name, VersionResponsibility and 
VersionRationale remain elements. I assume that VersionDate is in there 
as well.
- will the ReferenceType be revised as well and become attribute base 
and reflect the same approah as for identifiers? This would make it more 
compact.
- Have we defined a formatting regular expression for version. I do not 
particularly support non-numeric characters in version as they may not 
sort as well as numbers.

thanks
*P

Chris Nelson wrote:
> Joachim,
> I agree with option 4. This is, essentially, the way it is done in SDMX.
> Both the Id method and the URN method should be supported (as they are in
> the option). For referencing in SDMX we allow either or both of the full
> identifier by attributes (agency, id, version etc.) and URN. In other
words,
> if the URN is present then there is no need for the full identifier by
> attributes. Is this the intent here? 
>
> For specification of unique Ids, where the URN is composed from a
> pre-determined set of components that include the Id, I would prefer to
see
> the specification of the full identifier by attributes to be mandatory.
The
> URN could be optional  i.e. for specification the application is not
allowed
> to specify a URN on its own, as it is not allowed to specify "any" URN -
the
> URN must be composed to the rules of the DDI URN scheme which includes the
> unique Id. 
>
> For both referencing and specification, if both are supplied and there is
a
> mismatch between the URN and the full id by attributes, then one of them
> should take priority.
>
> Just a note, also about the Id as your example is not clear here. For a
> maintainable the id is the id of the maintainable. For a versionable or
> identifiable, it must also have the id of the maintainable within which it
> is contained e.g. when referencing a variable it is mandatory to identify
> also the variable scheme.
>
> Regards,
> Chris
>
> -----Original Message-----
> From: ddi-srg-bounces at icpsr.umich.edu
> [mailto:ddi-srg-bounces at icpsr.umich.edu] On Behalf Of Joachim Wackerow
> Sent: 29 October 2007 11:22
> To: Pascal Heus; DDI Technical Implementation Committee; Chris Nelson
> Subject: [DDI-SRG] TIC Meeting: Identifier issues
>
> Pascal, Chris, and others,
>
>
> We started today the meeting in Dagstuhl. We discussed again the
identifier
> issue. Please see the attached file for details. Currently we are all
opting
> for version number 4 (attributes) right now. We would like to think on
that.
> Do you have any opinions on that?
>
> Additional note:
> things like Name, VersionResponsibility and VersionRationale need to be
> elements in base abstract Identifier ComplexType.
>
> Pascal:
> We will discuss data types. Do you have any additional opinion on the
issue
> beyond the recorded issues in Mantis?
>
> Achim
>
>
>