PubDIDs (and DIDs in general, maybe)

[Patrick Dowler]

On 28/01/14 01:33 PM, Arnold Rots wrote:
> The advantage is that it can implement very flexible drilling into datasets
> without increasing the number of identifiers in the registry.

I agree with this goal 100%.

> In short: the persistent identifier registry only needs to be aware of the
> part in front of  '?' (%3F), and then it is up to the service to define what
> parameters it allows (and that functionality needs to be queriable, of course);
> potentially that single identifier can stand for an infinite number of
> identifier instances.
> I should add that it does not matter, of course, whether the persistent identifier's
> root is ivo://ADS/<something>.<something> or a DOI

There is one example of such identifiers in use today and it works 
exactly as designed: vospace resource identifiers. The general form is:

vos://<authority>/<path>

for example:

vos://cadc.nrc.ca!vospace/myProject/myFile

The resolution mechanism for the vos scheme is robust. You extract the 
vos scheme and authority, change the scheme to ivo, convert the special 
separators (! and ~) to /, concatenate, and that is the IVORN of the 
vospace in the registry. When you access the "nodes" resource of the 
service, you use the path from the vos URI as is.

The allowed separators are ! and ~. The ! has been in use since vospace 
1.0 and the ~ was introduced in 20 when we found that ! was pain for 
command-line tools. These are the only two characters one can use in 
that part of the URI without introducing any complex 
parsing/manipulation. Anyway, proven to work.


So, defining a new scheme with rules to find the ivorn of another 
resource is a proven option, but probably not one to take lightly. It 
does give you globaly unique, resolvable URIs without clobbering the 
query string or fragment (which services may want - eg vospace has views 
which can be invoked via a query string).

More fuel for the fire maybe :-)

-- 

Patrick Dowler
Canadian Astronomy Data Centre
National Research Council Canada
5071 West Saanich Road
Victoria, BC V9E 2E7

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