RE: BSBM With Triples and Mapped Relational Data in Virtuoso



> -----Original Message-----
> From: Orri Erling [mailto:erling@xs4all.nl]
> Sent: 12 August 2008 09:54
> To: Seaborne, Andy; 'Chris Bizer'; public-lod@w3.org
> Subject: RE: BSBM With Triples and Mapped Relational Data in Virtuoso
>
>
>
> Andy
>


> We have something of the sort on the SQL side, called a procedure view.  MS
> SQL Server calls such a thing a table valued function.  Anyway, it makes a
> result set and can take parameters that give a fixed value to some of the
> result columns.  Then there is a cost model hookthat allows specifying what
> cardinality and cost implications binding or not binding a result column may
> have.
>
> This is quite complex and general agreement would seem improbable to me.
>
> Please send a link to a description of how Arq addresses functions in
> queries.  It is in principle possible that we could implement a compatible
> syntax, for example on top of the aforementioned procedure views if the
> functionality is close.

(catching up ...)

This is related to a discussion in sparql-dev where I described the ARQ mechanism for something like table valued functions (not identical):

http://lists.w3.org/Archives/Public/public-sparql-dev/2008JulSep/0036.html


So yes and no.  It's improbable that a common interface to the implementation of custom functions but I can see that agreement on syntax and semantics on the side of the way it is expressed in a future SPARQL which helps the application writer if not the custom function implementer.


        Andy

Received on Monday, 18 August 2008 18:34:57 UTC