- From: Andy Seaborne <andy@apache.org>
- Date: Sun, 22 Jan 2023 13:24:10 +0000
- To: public-rdf-star-wg@w3.org
On 20/01/2023 23:27, Pierre-Antoine Champin wrote:
> Dear Souri,
...
> - it adds a "4th column" to every triple. IIUC, you seem to assume that
> all implementations already deal with some for of triple identifier, all
> we need is to expose it to the user. But I am not sure that all
> implementations have such an internal identifier (I am actually pretty
> sure that some don't).
Many systems, for persistent storage, intern RDF terms and that
implicitly gives a triple identifier as a concatenation of SPO. But they
work on quads so it is meaningless. And may change at a whim.
If in-memory, triples have value-equality-semantics, so two pointers to
two different areas of memory can represent the same triple even if the
terms are intern'ed are not the same reference. No single triple identifier.
> - somehow, it turns graphs, that are currently sets of triples, into
> multisets of triples. And multisets are tricky. What happens for example
> when you merge two graphs containing an identical triple? Is it the same
> triple? Two triples with different "default" identifiers? What appens
> when you use SPARQL UPDATE to remove a triple? Do you remove only one of
> them or all of them? Can of worm ahead...
The SPARQL Update question is a good question.
Andy
Received on Sunday, 22 January 2023 13:24:25 UTC