[gin-info] Possible list of subset data for info interop

[JP Navarro]

Thomas,

I think you're totally right that listing attributes without describing
the relationships between them is useless. Perhaps the disagreement is
about what "defining a schema" means.

One definition of schema is a verbal description of attribute  
relationships
and their cardinality.  Another interpretation is to define a specific
syntax or computer readable representation of the relationships and
cardinality.

We should define relationships and cardinality, but probably not syntax
or or representation, right?

JP

On Mar 2, 2006, at 10:17 AM, Dr. Thomas Soddemann wrote:

> Hi Jen,
>
> Jennifer M. Schopf wrote:
>> Thomas-
>>
>>    this group is NOT defining a schema.  This group is deciding on  
>> a minimal set of attributes for everyone to advertise in their  
>> native schemas.
>>
> don't worry, I have not suggested to come up with a new schema.
>
>> We will not have an NxN mapping - we will have a mapping of N  
>> schemas into one list of attributes. This space is also small - I  
>> believe we have only 3 schemas for folks involved now, the GLUE  
>> schema, CIM, and what the nordu-grid guys have used, which should  
>> be close to the GLUE schema since it grew out of MDS2 originally.
>>
> What is the value of the following attribute list?
>
> Queue name=small
> Queue name=large
> Queue name=huge
> GRAM version=4.0.1
> GRAM version=4.0.1
> GRAM version=3.9.5
> LRMS type=other
> LRMS type=SGE
> LRMS type=OpenPBS
> Total CPUs=128
> Total CPUs=64
> Total CPUs=2048
> Free CPUs=16
> Free CPUs=0
> Free CPUs=64
> Total Jobs=132
> Total Jobs=36
> Total Jobs=42
> Unique Id=1
> Unique Id=2
> Unique Id=4
>
>
> It is worthless, since one cannot know which data belong to the  
> same context/object (queue), unless one has some rule to structure  
> the data. A schema defines the attributes as well as their context.  
> A schema rule could e.g. be in the above case that every third  
> position (0, 3, 6,...; 1,4,7,...; and 2,5,8,...) belongs to the  
> same queue. Such a rules comes along with a schema but not with the  
> list of attributes.
> So we do need to agree on the structure the data are presented as  
> well as on the attributes our "objects" will have. And if we do not  
> want to invent another schema we should find a best match for our  
> minimum set of attributes we would like to see represented in such  
> an existing schema.
>
> In your first sentence you say that "This group is deciding on a  
> minimal set of attributes for everyone to advertise in their native  
> schemas."
> But exactly that leads to the n^2 problem. Everyone has to  
> understand each other's schema in order to correctly identify the  
> attributes from the minimum set.
>
> So what is so bad about the idea to use one schema as a kind of  
> master/interface schema and populate or use only the minimum set of  
> attributes we are going to agree on?
>
> Thomas
> <Thomas.Soddemann.vcf>