[sc34wg3] Possible TMRM issue

[Jack Park]

Let me first try to disambiguate "Proxies, in turn, are sets of
(proxy,proxy) pairs..."

My understanding of implementations of TMRM suggests that a proxy is a
collection (set) of property objects, each of which is a  {type,value} pair,
where type, itself is, indeed, a proxy, and value might or might not be a
proxy.  I'll trust that this is what Lars meant. Yes?

It has been suggested to me that, from a pure implementation perspective, a
proxy is just an API and need not actually be an object in its own right,
implying that a subject map is, at its simplest implementation level, a
collection of subject properties, each of which is associated with a
particular subject.

At the implementation level, there are options to satisfy the query issue
related to merge comparisons. Indexing comes to mind, and that can happen
either externally or internally to the database.  Having each propertyType
proxy keep track of all of its instances is one example.

I have a slightly extended riff on using applications, what I am now
interpreting to be called "legands",  to be fairly aggressive about
inventing their own PSIs based on a kind of subjectType, e.g. webpage, where
the core subject map (core Legand, I suppose) provides base values for those
PSIs. This permits each application to ask if the core PSI exists in the
database.

Not sure any of that helps, but I believe that implementations of the TMRM
need to pay attention to the concern Lars expresses here.
Jack

On 3/18/06, Lars Marius Garshol <larsga at ontopia.net> wrote:
>
>
> There is one potential TMRM issue that's worried me for a while, and
> I would appreciate if we could put it to rest one way or another.
>
> TMRM instances are sets of proxies, which implies that you can't have
> duplicate proxies. Proxies, in turn, are sets of (proxy, proxy)
> pairs, which gives you a simple, but recursive structure. How is it
> possible to efficiently detect duplicates in this model? In theory
> you may have to traverse the entire model every time you want to
> compare two proxies.
>
> I doubt that this has failed to occur to Robert, but I have no idea
> what the answer is, and would appreciate if this could be cleared up
> somehow.
>
> --
> Lars Marius Garshol, Ontopian               http://www.ontopia.net
> +47 98 21 55 50                             http://www.garshol.priv.no
>
>
> _______________________________________________
> sc34wg3 mailing list
> sc34wg3 at isotopicmaps.org
> http://www.isotopicmaps.org/mailman/listinfo/sc34wg3
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://www.petesbox.net/pipermail/sc34wg3/attachments/20060318/5e606119/attachment.html