Re: Reviving Semantic Relationships in Beagle

["Enrico Minack" <minack L3S de>]

Hi Kevin,

> ... it became apparent that it wasn't so much the storage of metadata
> that was important (lucene stores Properties, or 'Fields' just fine) but
> relationships between data.
right, Lucene is excelent in storing and querying fields (properties of 
resources are string values), but fails when you want to follow / exploit 
relations (references to other resources, which are stored in Lucene as 
strings refering to URIs of other lucene documents). An RDF store supports 
such a join natively, because it is the very nature of an RDF query to have 
joins / to contain relations.

> ... so I propose the following means of 'hooking up' a RDF store to 
> Beagle.
>
> -New Query_Part which allows a rdf type query (raw) against the store.
> -Wire into LuceneQueryDriver and LuceneIndexDriver to store new
> relationships in RDF store and query them upon creation of a Hit.
> -Add a more accessible API to Filter for Adding Parents/Children to
> indexables.
relations are not always parent - child relations, they usually refer to 
related resources. For instance, an email tells you something about people 
that send / received the email, so a relation between the email and the 
involved people can be created. Or the email contains a link to a web page, 
which is clicked and indexed by beagle later, so these resources can also be 
connected via a relation. But these examples are no parent - child 
relations, but still provide valuable information for the user to find 
resources / browse results. In RDF, there is no need to restrict the notion 
of a relation to a parent-child relation.

> While this seems like we are replicating much of the data in the
> Lucene Fields, this is actually something completely different, we are
> referencing an exact entity, not just a name, or subject. As a result
> of this tree, not only can we adjust our scoring to account for
> related items, but we can provide right-click options like 'See all
> files by this author' etc. in a more intelligent mannor.
right, storing these relations does not mean the replication of metadata 
(properties). With the URIs that can be found on both sides of a relation, 
you can get all metadata from the Lucene index. You only additionally store 
the relation, not the metadata that are associated with a URI.

Regards,
Enrico M.