Re: [Tracker] RDF graphs and full text search

[Martyn Russell <martyn lanedo com>]

On 03/09/10 15:06, Mildred Ki'Lya wrote:
> Hi,

Hi,

> I was wondering what exactly was a graph in SPARQL queries?
>
> For the moment, I only inszert triples in the database using an INSERT
> query. I also use DELETE sometimes to remove old values where I need to
> place the new values (which for some reason might have changed).
>
> But in the log files, and in the evolution plugin, I saw constructs of
> the form:
>
> DROP GRAPH<iri>
> INSERT INTO<iri>  {
>    <iri>  a ... ; ... .
> }
>
> How is that different to:
>
> INSERT {
>    <iri>  a ... ; ... .
> }

INSERT on its own may fail if there are cardinality issues with the data 
you're inserting. Additionally, there is no UPDATE with RDF, so we use 
DELETE/DROP with INSERT.

> I wondered if that had an effect on the Full Text Search in Tracker as I
> can't find anything using fts:match. If I am looking the word "Lucene"
> that is included in a message body (nmo:plainTextMessageContent), the
> following query don't return any results:
>
> SELECT ?x WHERE { ?x a nmo:Email ; fts:match "Lucene" . }

Where is "Lucene" actually stored?

--
Regards,
Martyn