Re: TMQL Proposal

We implemented transitive closure as a stored procedure using a 
well-known graph traversal algorithm - its not that hard to do.

Cheers,

Kal

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
>