- From: Steve Harris <steve.harris@garlik.com>
- Date: Tue, 26 Feb 2013 18:28:15 +0000
- To: Andy Seaborne <andy.seaborne@epimorphics.com>
- Cc: public-rdf-wg@w3.org
On 2013-02-26, at 17:46, Andy Seaborne <andy.seaborne@epimorphics.com> wrote: > On 26/02/13 16:36, Kingsley Idehen wrote: >> On 2/26/13 6:53 AM, Steve Harris wrote: >>> On 2013-02-26, at 11:21, William Waites <wwaites@tardis.ed.ac.uk> wrote: >>> >>>> On Tue, 26 Feb 2013 11:10:55 +0000, Steve Harris >>>> <steve.harris@garlik.com> said: >>>> >>>>> Yes, but this can only happen if you merge multiple datasets, >>>>> right? Otherwise no-one gets to write anything into the "default >>>>> graph" against the will of the dataset maintainer. >>>>> This is related to the reason why I find the idea of having a >>>>> single format that can express both Graphs and Datasets so scary >>>>> - you can bring this kind of situation on yourself without any >>>>> prior warning. Very bad idea. >>>> I agree, but this arises from the existing of a special graph called >>>> default and the somewhat non-standard use of the word "default". A >>>> longer but more accurate name might be, the "graph that cannot be >>>> named or referred to of which there is only one where we put triples >>>> that we can't think of a better place to put". >>>> >>>> This could easily be solved by putting >>>> >>>> default_graph = http://some.name/graph >>>> >>>> in your sparqlserver.ini file and then manage the contents of that >>>> named graph whatever way you see fit. >>>> >>>> We do not need the notion of "default graph" in the core RDF specs! It >>>> is a mistake. Please let us get rid of it. >>> I agree wholeheartedly, and argued quite vociferously against it's >>> inclusion in SPARQL 1.0, but I think it's too late now. The anonymous >>> genie is out of the bottle. >>> >>> - Steve >>> >> >> As implementers of SPARQL compliant stores and DBMS engines, we (you, >> Andy, I and others) do have the ability to conjure up our own best >> practices which could then cycle back to the next round of RDF and >> SPARQL specs related revisions. It's happened in the past, so why not >> handle this matter the same way? >> >> Conclusion: We discourage the use of anonymous default graphs in our >> respective products. Every useful thing should be denoted using an >> identifier. 4store and 5store out of the box have the "default graph" set to the RDF Union of the named graphs, and I don't know of any installations that have changed that config option, however… > Jena users find the default graph concept useful: > > 1/ When there is one graph being published > > 2/ As the union of the named graphs > > 3/ As a single place to put the manifest > > Conclusion: you don't have to use it if you don't want to. > > (all well worn points) Right, if people are genuinely finding it useful, I don't think it's reasonable to ask for it to be removed. 1-3 above /could/ be handed perfectly well in other ways, in a pure quad system. However, they weren't. C'est la vie. - Steve -- Steve Harris Experian +44 20 3042 4132 Registered in England and Wales 653331 VAT # 887 1335 93 80 Victoria Street, London, SW1E 5JL
Received on Tuesday, 26 February 2013 18:28:44 UTC