Re: New module proposal: tracker

[Philip Van Hoof <spam pvanhoof be>]

On Tue, 2009-08-18 at 17:50 +0200, Steve Frécinaux wrote:
> Xan Lopez wrote:
> > It can be used directly by applications that feed it data through an
> > API. Zeitgeist is an example, another could be bookmarks/history
> > storage in Epiphany.
> 
> Do you mean storing actual bookmarks into the database ?

> I would be quite reluctant in mixing actual data with rebuildable caches 

The tracker-store is not only about rebuildable caches. 

Again, tracker-miner-fs is just one data provider, like any other.

The Tracker project is not only about tracker-miner-fs, and Tracker's
purpose is not only to cache rebuildable data.

> (because when caches get in the way people are eager to just rm them).

The unique user data in Tracker isn't cache.

> An indexer mostly produces data that you can build again -- by running 
> the indexer once more.

Tracker's purpose is not only to cache rebuildable data.

> On which field does tracker-store play ?

The tracker-store is a desktop service that offers the application
developer a query capability against data that it stores. The data that
it stores must be strictly defined by a schema (which is what in RDF is
called an ontology). The schemas that we ship by default are the Nepomuk
ones. The query language is SPARQL. The service provides the opportunity
to the application developer to store. The application developer uses
the an extension to SPARQL, SPARQL Update, which we support too. The
communication between application and tracker-store happens over DBus.

Nepomuk's ontologies:
http://www.semanticdesktop.org/ontologies/

SPARQL:
http://www.w3.org/TR/rdf-sparql-query/

SPARQL Update:
http://jena.hpl.hp.com/~afs/SPARQL-Update.html

RDF:
http://www.w3.org/RDF/

Let me know if that was a helpful description for you. I tried hard not
to sound like an old German philosopher ;-).


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Philip Van Hoof, freelance software developer
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