Re: PROV-ISSUE-387 (unique-generation): generation [prov-dm-constraints]

Uniqueness and key constraints (concerning generation and many other relations) have been updated in the review version of PROV-CONSTRAINTS.  

I propose to resolve this issue by stating that the id is a key for generation (and many other relations), and that each entity has a unique generation, i.e. the entity determines the id.  There has been no discussion arguing against generation uniqueness, so I presume that making the intended behavior clear will address the issue.

This issue is marked as pending review, and anyone concerned about it should address it in reviewing PROV-CONSTRAINTS.

--James

On Jun 1, 2012, at 1:02 PM, Provenance Working Group Issue Tracker wrote:

> PROV-ISSUE-387 (unique-generation): generation [prov-dm-constraints]
> 
> http://www.w3.org/2011/prov/track/issues/387
> 
> Raised by: Luc Moreau
> On product: prov-dm-constraints
> 
> Hi,
> 
> In prov-constraints, we have unique-generation-time [1], which I believe
> follows from ordering constraints.
> 
> But it also has generation-uniqueness [2].
> 
> A previous version of the document [3] defined the constraint generation-uniqueness, but made it optional, for "well-behaved/proper/well-structured" provenance. 
> 
> Rationale for this was discussed in [4].
> 
> Benefit of generation-uniqueness is that new inferences such as derivation-use [5] are allowed.
> 
> prov-dm-constraints need to make this clear.
> 
> Cheers,
> Luc
> 
> 
> 
> 
> [1] http://dvcs.w3.org/hg/prov/raw-file/default/model/prov-constraints.html#unique-generation-time
> [2] http://dvcs.w3.org/hg/prov/raw-file/default/model/prov-constraints.html#generation-uniqueness
> [3] http://www.w3.org/TR/2012/WD-prov-dm-20120202/#structural-constraints
> [4] http://lists.w3.org/Archives/Public/public-prov-wg/2012May/0285.html
> [5] http://dvcs.w3.org/hg/prov/raw-file/default/model/prov-constraints.html#derivation-use
> 
> 
> 
> 


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Received on Wednesday, 18 July 2012 17:55:26 UTC