Re: Q: ISSUE-42 bNode semantics

Personally I believe that is is already an achievement to cover conjunctive queries, namely select-project-join / positive select-from-where (SQL) and BGPs (SPARQL).

On 21 May 2011, at 16:23, Richard Cyganiak <richard@cyganiak.de> wrote:

> On 20 May 2011, at 23:04, Enrico Franconi wrote:
>>> Your argument hinges on a claim that one proposal is correct, and another is incorrect. Can you state the criteria that an RDB2RDF mapping has to fulfill so that you consider it correct and complete?
>> 
>> As I say in the wiki, I consider the query answering (QA) problem. A translation from data and queries in RDB/SQL to RDF/SPARQL is sound whenever any tuple returned in the translated QA problem is also returned in the original QA problem; it is complete if any tuple returned in the original QA problem is also returned in the translated QA problem.
> 
> What expressivity of queries does the translation of queries have to cover? SPARQL, SQL or something else?
> 
> Thanks,
> Richard

Received on Saturday, 21 May 2011 14:41:05 UTC