[rdfweb-dev] The Scutter Volume problem

Julian Bond julian_bond at voidstar.com
Wed Mar 17 08:35:56 UTC 2004


Morten Frederiksen <mof-rdf at mfd-consult.dk> wrote:
>I use the Redland [1] library for storing triples,

Is there a binary distribution of Redland for use with PHP and MS 
Windows yet? Without that I can't use it and I'd like to.

>> Does it mean that FOAF is only really useful as a data transfer protocol
>> where the data is discarded immediately after being used?
>Partially yes, nobody is interested in having stale and unused data lying
>around. But this is not much different from the old web, your browser may
>have a cache, but in general all you save are the links.

Looking at the wiki page for application ideas 
(http://rdfweb.org/topic/ApplicationIdeas), maybe 1/3 of them require a 
local smushed data store of triples. Even though moderately old data is 
still useful, I think you have to solve the data expiry problem in the 
original design. It's too easy to simply ignore it, but that will bite 
you later. As we're trying to synchronise a local store with the 
originals, we have to deal with modify and delete as well as add and the 
only way to do this is by triple. Once the data has been smushed it's 
too hard to find the original source.

So I think you end up with designs where you store as little as possible 
locally and go back and retrieve the original wherever you can. This 
actually has implications for feed design as well, around the 
discussions on PPD, made, maker, topic etc[1].

Most of this came from trying to build RateMyFoaf and FoafCollage and 
their interaction with things like Plink. I keep getting forced back to 
dealing with individual FOAF files and displaying only the contents of 
that file without smushing it with other files.

There are lots of other application ideas and use cases where these 
issues don't arise because the app is only interested in a single file. 
So all I'm saying is that building aggregators is hard. But I guess we 
knew that.

[1]I see PPD is in the spec now. It would be good if we all started 
using it.

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