Hi,
I've gotten a couple of queries about whether we came to a concensus on
identifiers, and if so, what was it. The answer to the first is yes, for
the most part (though discussion remains open through the standardization
process).
Here's a summary of what the main ideas as I understand them. I am
working on a Working Draft that will spell it out in more detail.
- IVOA identifiers refer to registered resources. Given an IVOA ID, one
should be able to resolve it to a description of the resource it
refers using some registry.
- IVOA IDs have two forms: an XML form and a URI form.
- The IVOA ID has two components: an AuthorityID and a ResourceKey
- The AuthorityID...
o establishes a namespace for related resources
o is "owned" or controled by an organization the manages the
resources within the namespace.
o must be uniquely "owned". This standard does not define the
mechanism by which AuthorityIDs are ensured or encouraged to be
unique or their ownership otherwise assertained. It is expected
that a central IVOA authority service of some kind will be
necessary to check for ownership.
o is recommended to be in the form of a DNS hostname.
o will be limited in the characters that can be used to form it.
- An organization may "own" several AuthorityIDs as it deems useful.
- The ResourceKey...
o is an identifier to a specific resource relative to the namespace
set by the AuthorityID.
o is in complete control of the organization "owning" the
AuthorityID.
o will be limited in the characters that can be used to form it.
- The XML form of the ID will look like this:
<ResourceID>
<AuthorityID>adil.ncsa.uiuc.edu</AuthorityID>
<ResourceKey>surveys/96.JC.01</ResourceKey>
</ResourceID>
8. The URI form will look something like this:
ivo://adil.ncsa.uiuc.edu/surveys/96.JC.01
Other notes:
- Record-level Keys were dropped from this proposal as it was thought
that the requirements for rendering components of a resource may be
different in different contexts.
- Can IDs have semantic content? They can but they are not recognized
within the context of this IVOA standard
- IDs do not address the problems of transience or replication. These
will be addressed in a separate recommendation built on top of
registries and this ID standard.
cheers,
Ray
Received on 2003-06-17Z00:20:52