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Re: PROV-ISSUE-247: Regarding Collections in prov-dm [prov-dm]

From: Khalid Belhajjame <Khalid.Belhajjame@cs.man.ac.uk>
Date: Wed, 08 Feb 2012 12:55:01 +0000
Message-ID: <4F3270A5.6040908@cs.man.ac.uk>
To: Paolo Missier <Paolo.Missier@ncl.ac.uk>
CC: Provenance Working Group <public-prov-wg@w3.org>

Thanks Paolo for the prompt reply.
I get your point.

PS: I am happy for you to close the issue.

khalid

On 08/02/2012 11:40, Paolo Missier wrote:
> Hi Khalid
>
> Like generation, these are designed to state the effect of some 
> operation on the data, rather than the operation itself -- I agree 
> that the operations change the state of a data structure. However 
> these are not operations per se: they express the relationship between 
> two states (before and after insertion). Also, calling them operations 
> would be a departure from our established structure.
> But in an early report on modelling the provenance of collections, I 
> made it clear that the inferences that you could do on the provenance 
> assertions depends on the type of the operations performed (insert, 
> delete, retrieve, create). So that's where operations came to the 
> foreground. Too bad the report never saw the light and it would now 
> need to be re-written.
>
>> "CollectionAfterRemoval(c2,c1, k) denotes that collection c2 
>> represents the removal of pair (k,v) from c1, where v is the value 
>> corresponding to key k in c1."
>>
>> I don't think we should specify the value "v".
> no problems to rephrase
>
> -Paolo
>
>
>
>
> On 2/8/12 10:22 AM, Provenance Working Group Issue Tracker wrote:
>> PROV-ISSUE-247: Regarding Collections in prov-dm [prov-dm]
>>
>> http://www.w3.org/2011/prov/track/issues/247
>>
>> Raised by: Khalid Belhajjame
>> On product: prov-dm
>>
>>
>> Hi,
>>
>> In section 6.8, two relations are introduced to model insertion and 
>> deletion of key-value pairs:
>>
>> "CollectionAfterInsertion(c2,c1, k, v) denotes that collection c2 
>> represents the new state of collection c1, following the insertion of 
>> pair (k,v) into c1"
>>
>> "CollectionAfterRemoval(c2,c1, k) denotes that collection c2 
>> represents the removal of pair (k,v) from c1, where v is the value 
>> corresponding to key k in c1."
>>
>> I am wondering if the above relations should be introduced as 
>> "operations" not as "relations". Defining them as relation would mean 
>> IMO that the collections c1 and c2 can be created independently and 
>> the only thing that matters is that  one collection contains a 
>> key-value pair that the other does not. Instead, from the definition, 
>> I think that both CollectionAfterInsertion(c2,c1, k, v) and 
>> CollectionAfterRemoval(c2,c1, k) were intended to modify the state of 
>> the world. For example, CollectionAfterInsertion(c2,c1, k, v) would 
>> change the state of the collection of c2 and replace it with the 
>> collection that is obtained by inserting the pair<k,v>  to c1.
>>
>> The second observation is with respect to the definition of 
>> CollectionAfterRemoval.
>>
>> "CollectionAfterRemoval(c2,c1, k) denotes that collection c2 
>> represents the removal of pair (k,v) from c1, where v is the value 
>> corresponding to key k in c1."
>>
>> I don't think we should specify the value "v".
>>
>> Thanks, khalid
>>
>>
>>
>
>
Received on Wednesday, 8 February 2012 12:58:15 GMT

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