[tmql-wg] TMQL Proposal
Tue, 1 Feb 2005 18:54:18 +0000
We implemented transitive closure as a stored procedure using a
well-known graph traversal algorithm - its not that hard to do.
On 1 Feb 2005, at 18:30, Stefan Lischke wrote:
> 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
> 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
> 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
>> 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
> My place : http://user.cs.tu-berlin.de/~lischke