RE: Performance issues with OWL Reasoners

>   KV> 1. ABox reasoning (reasoning about instance data). Scalability
>   KV> here is being achieved here by leveraging relational database
>   KV> technology (which is acknowledged to be scalable) and mapping
>   KV> OWL instance reasoning operations to appropriate SQL queries on
>   KV> the underlying data store.
> 
> I may be wrong here, but as far as I know the expressivity of OWL-DL,
> for example, is too different from that of RDBMS for this to work
> completely. I am not enough of an expert to know if this sort of
> mapping is possible at all or whether it just cannot be done
> efficiently.

[VK] You may have a point Phil! It is definitely possible as various approaches
have explored mapping various DL constructs to views involving
relational algebra operations.

See section 5 in 
http://lsdis.cs.uga.edu/~kashyap/publications/MIKS00-DAPD.pdf 

However, this was done primarily for CLASSIC and other DLs which were possibly
less expressive than OWL-DL and FACT. I was wondering if the current
implementations of DL reasoners such as Pellet, Racer, etc. adopt this strategy.

> Having said that there is a similar approach, which uses RDBMS. For
> example, the instance store (http://instancestore.man.ac.uk) which I
> was briefly involved with (before the backend got to hard for my poor
> brain!), uses a metaschema backend. Queries are not made by mapping to
> SQL, but using SQL and reasoner queries together.

[VK] Maybe the increased expressivity of OWL-DL leads to the above design choice
of SQL + reasoning.

>   KV> 2. TBox reasoning scalability is a challenge, especially at the
>   KV>    scale of 100s of
>   KV> thousands of classes found in medical ontologies. Would love to
>   KV> hear >From DL experts on this issue.
> 
> Again, as far as I understand, the complexity of T-Box and A-Box
> reasoning for logics such as that underlying OWL-DL are not that
> different (i.e. they are both terrible!), so the issues are much the
> same.


> http://www.cs.man.ac.uk/~dturi/papers/instancestore2.pdf

[VK] Thanks for this. Will look this up.

Cheers,

---Vipul