Re: TMQL Proposal

On Wed, Feb 02, 2005 at 02:16:45AM +0100, Stefan Lischke wrote:
> As Lars pointed out, this abstract language could be implemented with 
> TMRQL or for example XQuery (like plan to do it for my XTM4XMLDB) or 
> with some other native stuff.

Oho! I would be very interested to be involved in this!

> LMG and Robert, can you guys point out if and how graph functions, which 
> i talked about (traversal, matching..), can be represented using the 
> latest TMQL approach?
> Or is it outside the requirement scope? If so, i have to say sorry to 
> Kal, than thats not a strong argument against TMRQL

Stefan,

I am not sure whether TMQL will hit your mark as 'graph traversal
language', but as one of the central (lower-level) parts of the
language we plan to have path expressions which should allow you to
traverse a map along associations. This is if you prefer to 'land'
somewhere in the map and then to move relative from there. There is
also a matching component to help you with that 'landing', rather
similar as tolog allows you to do now. And, of course, you can mix
these styles, as I often do.

\rho

> >On 1 Feb 2005, at 18:30, Stefan Lischke wrote:
> >
> >>Hi,
> >>
> >>I have some points about this proposal.
> >>
> >>In my head a topic map is represented as a graph of information items 
> >>(defined by TMDM). For me the big advantage of topic maps is the 
> >>abstraction in the model. We dont spend any time on thinking about 
> >>"how" all our information items are connected. Therefor we created 
> >>the abstract model TMDM. A Topic plays a role in an AssociationRole 
> >>which is contained in an Association which may contain other 
> >>AssociationRole. (plays and contains are edges)
> >>With that i can imagine a huge topic map graph of all those TMDM 
> >>defined information items.
> >>
> >>But when looking at TMRQL, i have to change from a graph in my mind 
> >>to a bunch of tables which are interconnected via id's.
> >>
> >>The proposal says:
> >>"One of the inherent principles that is embodied in the views 
> >>approach is that every topic map object (topic, name, occurrence etc) 
> >>has some kind of system identity."
> >>
> >>That is definitely true, from the view of a Topic Map Engine 
> >>developer. There has to be an identity for every information item.
> >>
> >>But in my opinion it is not necessary for the user who works with 
> >>topic maps. The user who creates a query must be able to stay in his 
> >>abstract graph representation/imagination.
> >>
> >>If the actual TMQL proposal fits to that needs is another question.
> >>
> >>I researched about Graph Query Languages and subGraph Matching 
> >>(especially efficient approaches with neural nets).
> >>
> >>Kal maybe you can convince me. That i can stay by the graph 
> >>representation in my mind and work with TMRQL.
> >>How could i express the following query with TMRQL:
> >>
> >>"Give me a subgraph of the TM, that contains a topic A, that has a 
> >>path to topic B and C."
> >>
> >>The problem of this query is the "path" operator, which is often used 
> >>in Graph Query Languages. A path in a topic map is a chain of  
> >>topic->assocRole->assoc->assocRole->topic->assocRole->assoc->......
> >>
> >>Such queries are very common. For example in semantic enhanced search 
> >>engines, where you can enter the words A, B, C. You'll get all 
> >>occurrences of the subgraph that contains A, B, C as result.
> >>
> >>just my 2c
> >>
> >>Stefan
> >>
> >>
> >>Kal Ahmed wrote:
> >>
> >>>Dear all,
> >>>
> >>>Graham and I have published a paper proposing a different approach 
> >>>to topic map querying. Rather than define a new query language, we 
> >>>define a relational view of the topic map data model which can then 
> >>>be queried using a standard relational query language such as SQL.
> >>>
> >>>Full details, including worked examples of the TMQL Use Cases which 
> >>>run on TMCore05 can be found at 
> >>>http://www.networkedplanet.com/download/TMRQL.pdf
> >>>
> >>>We would like this document to be taken as input from Networked 
> >>>Planet Limited into the ISO TMQL standardisation process.
> >>>
> >>>Best regards,
> >>>
> >>>Kal Ahmed
> >>>
> >>>_______________________________________________
> >>>tmql-wg mailing list
> >>>[email protected]
> >>>http://www.isotopicmaps.org/mailman/listinfo/tmql-wg
> >>>
> >>
> >>
> >>-- 
> >>My place : http://user.cs.tu-berlin.de/~lischke
> >>
> >
> >_______________________________________________
> >tmql-wg mailing list
> >[email protected]
> >http://www.isotopicmaps.org/mailman/listinfo/tmql-wg
> >
> 
> 
> -- 
> My place : http://user.cs.tu-berlin.de/~lischke
> 
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