Re: Proposing Tracker for inclusion into GNOME 2.18

[Jamie McCracken <jamiemcc blueyonder co uk>]

Wouter Bolsterlee wrote:
> 2006-10-25 klockan 12:27 skrev Jamie McCracken:
> > Ross Burton wrote:
> > > On Wed, 2006-10-25 at 11:12 +0100, Jamie McCracken wrote:
> > > > > > With everything mapped 1:1 you can then use RDF query to search them
> > > > > Why would you need a 1:1 mapping to do a query?  A query for "contacts
> > > > > with an email of jamiecc blueyonder co uk" should be possible
> > > > > independent of the number of email addresses a contact can have.
> > > > we need the 1:1 mapping to get/set the values. Whatever we implement we 
> > > > must have a unique metadata name for a particular service in order to do 
> > > > that otherwise getting or setting a value would be impossible.
> > > >
> > > > One problem with metadata relationships is that some metadata like in 
> > > > the above case would only be searchable like Contact.JabberID as the 
> > > > actual storage would be in Contact.WorkJabberID or Contact.HomeJabberID 
> > > > so it might get confusing for developers if they try and get the value 
> > > > of Contact.JabberID which would be NULL.
> > > A real world, physical example:
> > >
> > > Name: Ross Burton
> > > Email address (personal): ross burtonini com
> > > Email address (personal): ross burton gmail com
> > > Email address (work): ross openedhand com
> > >
> > > How would you store this in Tracker?  If we declare that Tracker Contact
> > > objects are *not* vCard clones I can handle dropping the personal/work
> > > annotations for now.
> > would suggest:
> >
> > Contact.HomeEmailAddress : ross burtonini com;ross burton gmail com
> > Contact.WorkEmailAddress : ross openedhand com
> >
> > note using semicolon as delimiter so contents would need to be escaped 
> > for the semicolon. I guess standardising on semicolon delimiters might 
> > be a good idea?
>
> Looks pretty useless to me. Delimiters in database field?
>
> The RDF way would be (triples):
>
>   hasPersonalEmail --- rdfs:subPropertyOf ---> hasEmail
>   hasWorkEmail     --- rdfs:subPropertyOf ---> hasEmail
>   RossBurton       --- hasWorkEmail       ---> ross openedhand com
>   RossBurton       --- hasPersonalEmail   ---> ross burtonini com
>   RossBurton       --- hasPersonalEmail   ---> ross burton gmail com
>
> You would then be able to query on "hasEmail" and get all three addresses.

okay that looks nice.

I will add some kind of triple store (ie use three tables instead of the 
current two tracker uses for metadata).

I dont have plans to turn tracker into a full semantic web thing but I 
do want to take advantage of this in the simplest way possible.

Thanks for showing me the "light" :)

--
Mr Jamie McCracken
http://jamiemcc.livejournal.com/