[redland-dev] Why not yet implement models aggregation?

[Dave Beckett]

Guo Mark-A21033 wrote:
> Hi,
> 
>    I noticed that the author of Redland had ever considered models
> aggregation and left a place
> in the API of Model to add sub-Models for this feature. But it seemed
> Dave never got round to
> implementing it even in the latest release.

That's right.  I decided to not implement things before I needed them
since those are the things that get the least testing.

If you need it, you should implement it yourself.

>    _I want to implement a high-level function for aggregating RDF
> models, which lies in caller layer _
> _not in RDF librdf. _My concern is that this approach will decrease the
> performance for querying data.

It will somewhat.

> Another idea is to add such implementation in librdf_model APIs. This
> would introduce another
> problem, that is, it will destroy the architecture of 1-to-1 mapping
> between model and storage in legacy 
> Redland implementation.

That is why there there is a librdf_model_storage implementation,
to make a union model implementation librdf_model_union (say),
it would present the same interface to the top level system.

Everything should work when a model is used in this way.

> 
>    Are there any better mechanisms for implementing join-model
> functionality? I’m very appreciated
> 
> if some one can give comments with similar experience.


Dave