I think that it would be a mistake to think of data as some sort of abstraction of a file. Certainly file-like things are an instance of data. But there are others: relational databases, object oriented databases, XML databases, streams of data (although streams are out of scope for V1 of the data architecture).

Allen Luniewski
IBM Cross Brand Services
IBM Silicon Valley Laboratory
555 Bailey Ave.
San Jose, CA 95141

408-463-2255
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Inactive hide details for "Donal K. Fellows" <donal.k.fellows@manchester.ac.uk>"Donal K. Fellows" <donal.k.fellows@manchester.ac.uk>


          "Donal K. Fellows" <donal.k.fellows@manchester.ac.uk>

          07/07/2007 10:43 AM

To

guru prasad <guru_bn@yahoo.com>

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Allen Luniewski/Almaden/IBM@IBMUS, Dave Berry <daveb@nesc.ac.uk>, ogsa-d-wg@ogf.org, ogsa-wg <ogsa-wg@ogf.org>

Subject

Re: [ogsa-wg] [OGSA-D-WG] Definition of "data service"

guru prasad wrote:
> Thank you for your comments Allen.
>
> In that case I vote for Dave Berry's definition:
>
> "A service that provides interfaces to the capabilities and data of one
> or more data resources within a service-oriented architecture."

There is a separate question as to whether the data *is* a capability; I
suspect it is, at least in some abstract sense. On the other hand, you
might wish to distinguish the data as a special kind of capability that
needs non-generic handling.

> and the Data Resource is .....

A data resource is an abstraction of a file, so I'd imagine that you'd
want to describe it as a resource that is an ordered collection of
organized information. (The idea is that it doesn't have to be in a
file, but it does have many file-like characteristics.) It's strongly
beneficial to the overall OGSA if you can have data resources being a
subclass of resources (by referencing the OGSA glossary).

Donal.