[Esip-preserve] On Earth Science Data File Uniqueness

[Curt Tilmes]

On 02/09/11 14:27, Bruce Barkstrom wrote:

> My argument is "where do you go to get metadata when all you've got
> is an ID?"

But what are you arguing?  That we shouldn't assign IDs?  Or that we
need a way to get the metadata? (again -- I agree -- we need a way to
get the metadata)

I just can't follow the connection that because you don't have a
central registry that will resolve and give you the metadata therefore
you shouldn't assign unique identifiers to your objects.  Those seem
to be distinct problems.

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I have a file (an object).

I need a way to identify and distinguish it from others.

I need a way to resolve and discover its metadata.

Assigning UUIDs to each object will allow me to identify and
distinguish objects from one another.

Assigning UUIDs alone will not allow me to resolve and discover the
metadata.

...

Therefore we should not assign UUIDs to the object.
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I'm missing something here.


> UUID's are fine - but certainly don't contain redirection addresses.
> To paraphrase, "knowing that this file is called 'Bob' doesn't tell
> me which family to call to find out where I should return him, nor
> does it tell me what format he's in."  So where do we get that.  In
> human terms, where do we find his birth certificate?  This is kind
> of an inverse to the problem "given an ID, where do I find a file?"
> which is the locator use case problem.  This one is "I've got an ID
> and a file, where do I go to find out about if if that's all I've
> got?"

If you just have the file, without an identifier, you have the same
problem.

Assigning an ID doesn't address the problem of where you go to get the
metadata.  It addresses the problem of how we identify and distinguish
files.

>     On 02/09/11 10:14, Bruce Barkstrom wrote:
>     > The question on my mind is sort of "If you come across a file with a
>     > UUID, who produced it?"
> 
>     I agree, that is an important question and needs to be addressed, but
>     UUID doesn't address it, nor was it intended to.
> 
>     > This isn't quite the same as the unique locator use case in the
>     > paper, since the question isn't "which sources could provide me with
>     > an authentic copy of a particular kind of file?"  It's more along
>     > the line of "where did this fellow 'Bakak' come from?"
> 
>     Sure, but without the identifier, you would still have the question
>     "where did this fellow come from?"  to which the response is "Who are
>     you talking about?"
> 
>     The identifier at least allows you to refer to him by name..
> 
>     Is your argument that we SHOULD have good metadata (I agree), or that
>     we SHOULD NOT assign UUIDs?

Curt