Re: [Zope-dev] RDF Musings and TinyTables - QL
[cut] > > Semantic Web are based on RDF: > > One path might be (not only one): > > RDF -> DAML+OIL -> OIL -> Description Logics further for example FaCT -> ALC > > and so on. > > Please don't use so many new acronyms. DAML and OIL are weird enough. > FaCT? ALC? I have no idea what you just suggested. :-) > My idea was that one can stay with RDF, RDFS, other will want OIL or DAML compatibile, and so on:) All depends on what one want RDF storage, ontologies or semantic web:) [Firstly OIL is based/uses description logic. FaCT (Fast Classification of Terminologies) is description logic system -classifier, reasoner. http://www.cs.man.ac.uk/~horrocks/FaCT/] [cut] > > You can implement RDF almost in any SQL language, and be able to Query > > rdfs. > > What does that mean? Do you mean that an RDF database could have a SQL > query interface? There is RDF Query Specification: http://www.w3.org/TandS/QL/QL98/pp/rdfquery.html Also there is DAML QL: http://www.daml.org/dql/ Check python's APIs:"RDFLib": http://rdflib.net/2002/11/05/rdflib-1.1.0/ (may use ZODB) There are also implemetation afaik in Java, php that store RDF in database, and alow you to query it. The best resourse list, I've seen, about RDF is "Dave Beckett's Resource Description Framework (RDF) Resource Guide": http://ilrt.org/discovery/rdf/resources/ search it for "query" or "python". [cut] > > I also consider this idea but I would do it more like RDFS - Folder like > > object with (rdf) properties containing other objects (subclasses). This is > > about "5" minutes of programing. > > I don't know what you're suggesting. > Shortly RDF can be thought as triples, in RDFSchema you have classes, subclasses:) If you think of folder as a class, you can inherite in sens of acquisition, but the main problem is multiple-inheritance, acquisition can work but makes it more complicated:). Lukasz ___ Zope-Dev maillist - [EMAIL PROTECTED] http://mail.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://mail.zope.org/mailman/listinfo/zope-announce http://mail.zope.org/mailman/listinfo/zope )
Re: [Zope-dev] RDF Musings and TinyTables
Hi Shane Below is a posting from David McCusker who is working on the backedn of Chandler. === From: Rys (David) McCusker <[EMAIL PROTECTED]> Subject: Re: repository access protocol Re: [Design] Knowing when you've read Tim Hoffman wrote: > Any hints as to how RDF will bu used in conjunction. that is one of the things that makes database design hard. Specifically, jumping through that hoop is one of the degrees of difficulty making the problem harder to solve. Additional degrees of difficulty include things like: *make it network protocol centric *make it fast and scale very large *use existing technology *write custom code for optimization *let the application coders see Python interfaces *make the local case faster than their remote case *make a centralized authorization case work *make the decentralized P2P good and attractive but that's just a sample. As you can see, it's hard to do justice to every priority. In many cases, we cannot give full-blown support to every iota of associated features one might think of in conjunction with one of the priority items. So we need some restrictions. In the case of RDF, we want to support it, and yet we do not want to compromise any of the priorities in pursuit of every feature folks associate with RDF usage. so our solution is that and RDF style application can see any of our content as if it was native to RDF. In other words, there is a mapping from our content to RDF. So you can get our content exported to RDF, among other things. Even more than this, some of Chandler application code wants to use RDF centric schema systems, with direct expression of this met information available at runtime. Katie has proposed a good an interesting system we will used to represent RDF meta information through python interfaces, by putting this information into classes, so RDF reflection features are visible as python APIs. However, consider some random feature of another RDF environment or application, call his feature X. we might not support X in Chandler -- at least, there might be no efficient way to do it, and we won't care. this means we do not aim to do every kind of RDF feature well in Chandler. We only aim to let the data we support the view in RDF terms. So there is a mapping in one direction outward to RDF, but there is not always a mapping the other way inward from RDF. > ie will RDF be used to map/find/query things in the > repository? we had not considered to using RDF specific query language so far in discussions. The repository access protocol will support more than one query language, and provide means to ask which one is supported in a given server. So in principle, a RAP server might use RDF in a query language and advertise this in the protocol dynamically. on the topic of query languages, we are not much further along than committing to more than one query language selectable dynamically at runtime. > and would this map to RAP access patterns ? I imagine it's possible to implement some kind of RDF system which is implemented in terms of RAP, because RDF is notorious for making no guarantees about performance, so one might iterate over every data item in a database in order to satisfy an RDF query. >(probably not using the correct terminology here) I'm not very particular about fashionable jargon as long as I understand what you mean. I prefer the informal approach to describing things anyway. -- Rys _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ Open Source Applications Foundation "Design" mailing list http://lists.osafoundation.org/mailman/listinfo/design On Fri, 2003-02-21 at 10:30, Shane Hathaway wrote: > On 02/20/2003 09:06 PM, Tim Hoffman wrote: > > In case your not aware Chandler OSAfoundation is basing their > > new PIM on RDF/ZODB/Python etc... > > > > if you haven't already it might be worth having a look at how they see > > RDF fitting into the picture. > > > > http://www.osafoundation.org/Chandler_rel._0.1.htm > > Wow, that's exactly what I was looking for. I guess I'll find out more > when they open up their CVS. I hope it's soon. If they've had any > difficulty persisting ZODB objects to RDF, I bet I could help them. > > Shane > > > ___ > Zope-Dev maillist - [EMAIL PROTECTED] > http://mail.zope.org/mailman/listinfo/zope-dev > ** No cross posts or HTML encoding! ** > (Related lists - > http://mail.zope.org/mailman/listinfo/zope-announce > http://mail.zope.org/mailman/listinfo/zope ) ___ Zope-Dev maillist - [EMAIL PROTECTED] http://mail.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://mail.zope.org/mailman/listinfo/zope-announce http://mail.zope.org/mailman/listinfo/zope )
Re: [Zope-dev] RDF Musings and TinyTables
On 02/20/2003 09:06 PM, Tim Hoffman wrote: In case your not aware Chandler OSAfoundation is basing their new PIM on RDF/ZODB/Python etc... if you haven't already it might be worth having a look at how they see RDF fitting into the picture. http://www.osafoundation.org/Chandler_rel._0.1.htm Wow, that's exactly what I was looking for. I guess I'll find out more when they open up their CVS. I hope it's soon. If they've had any difficulty persisting ZODB objects to RDF, I bet I could help them. Shane ___ Zope-Dev maillist - [EMAIL PROTECTED] http://mail.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://mail.zope.org/mailman/listinfo/zope-announce http://mail.zope.org/mailman/listinfo/zope )
Re: [Zope-dev] RDF Musings and TinyTables
Hi Shane In case your not aware Chandler OSAfoundation is basing their new PIM on RDF/ZODB/Python etc... if you haven't already it might be worth having a look at how they see RDF fitting into the picture. http://www.osafoundation.org/Chandler_rel._0.1.htm See ya Tim On Wed, 2003-02-19 at 03:21, Shane Hathaway wrote: > I just read the RDF article published here: > > http://www.xml.com/pub/a/2003/02/12/rdflib.html > > I've understood the mechanics of RDF for a while, but never understood > what makes it better than what we already have. Now I think I get it: > RDF theory is a new kind of database abstraction. It's similar to a > relational database in that you put pieces of data into the database and > later search for data. But it's much more ad-hoc than a relational > database. > > Serialization of RDF into XML and the relationship between RDF and the > Semantic Web are distinct concepts from RDF theory. > > This ad-hoc data storage made me think of TinyTables. TinyTables is a > good Zope product that fills the need for simple tables of data, but it > needs attention. What if it got replaced by some Zope product called > "RDFBucket"? An RDFBucket object would let you input data in a variety > of ways, including object introspection, forms, and XML with embedded > RDF. It would let you run queries similar to ZCatalog. Maybe it would > also generate RDF for embedding metadata in web pages. > > I'm wondering if I'm thinking in line with RDF theory, or if I've veered > off track. If you're familiar with RDF: What do you think? > > Shane > > > ___ > Zope-Dev maillist - [EMAIL PROTECTED] > http://mail.zope.org/mailman/listinfo/zope-dev > ** No cross posts or HTML encoding! ** > (Related lists - > http://mail.zope.org/mailman/listinfo/zope-announce > http://mail.zope.org/mailman/listinfo/zope ) ___ Zope-Dev maillist - [EMAIL PROTECTED] http://mail.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://mail.zope.org/mailman/listinfo/zope-announce http://mail.zope.org/mailman/listinfo/zope )
Re: [Zope-dev] RDF Musings and TinyTables
Lukasz Racon wrote: I just read the RDF article published here: http://www.xml.com/pub/a/2003/02/12/rdflib.html I've understood the mechanics of RDF for a while, but never understood what makes it better than what we already have. Now I think I get it: RDF theory is a new kind of database abstraction. It is NOT just abstraction:) The point is you can read RDF and understand it, and machine can understand it too, what makes Web a huge database (of course in future). Its not just HTML or XML it is structured text, so for example you can search web - based on logic (like searching in library catalog), and not like to day - which is just matching words. In other words now you have content, RDF gives you content and metadata (content description). Ontologies are next step which gives you relation between objects and so on. That's all fine and good, but I'd like someone to confirm my thinking: that the *core principle* of RDF is a new database abstraction. I believe that all the other concepts derive from this core principle. It's similar to a relational database in that you put pieces of data into the database and later search for data. But it's much more ad-hoc than a relational database. Serialization of RDF into XML and the relationship between RDF and the Semantic Web are distinct concepts from RDF theory. Semantic Web are based on RDF: One path might be (not only one): RDF -> DAML+OIL -> OIL -> Description Logics further for example FaCT -> ALC and so on. Please don't use so many new acronyms. DAML and OIL are weird enough. FaCT? ALC? I have no idea what you just suggested. :-) This ad-hoc data storage made me think of TinyTables. TinyTables is a good Zope product that fills the need for simple tables of data, but it needs attention. What if it got replaced by some Zope product called "RDFBucket"? An RDFBucket object would let you input data in a variety of ways, including object introspection, forms, and XML with embedded RDF. It would let you run queries similar to ZCatalog. Maybe it would also generate RDF for embedding metadata in web pages. 1st idea: You can implement RDF almost in any SQL language, and be able to Query rdfs. What does that mean? Do you mean that an RDF database could have a SQL query interface? 3rd idea: I haven't done research on RDF and Zope/Python, yet, but it seams to be a good idea to do something like "RDFBucket" especialy using ZODB (maybe not derivied from TinyTable). I will not derive anything from TinyTable. That would not be pretty. I also consider this idea but I would do it more like RDFS - Folder like object with (rdf) properties containing other objects (subclasses). This is about "5" minutes of programing. I don't know what you're suggesting. Hope this gives you some light:) Right now, I'm looking for milk, not meat. :-) Shane ___ Zope-Dev maillist - [EMAIL PROTECTED] http://mail.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://mail.zope.org/mailman/listinfo/zope-announce http://mail.zope.org/mailman/listinfo/zope )
Re: [Zope-dev] RDF Musings and TinyTables
> I just read the RDF article published here: > > http://www.xml.com/pub/a/2003/02/12/rdflib.html > > I've understood the mechanics of RDF for a while, but never understood > what makes it better than what we already have. Now I think I get it: > RDF theory is a new kind of database abstraction. It is NOT just abstraction:) The point is you can read RDF and understand it, and machine can understand it too, what makes Web a huge database (of course in future). Its not just HTML or XML it is structured text, so for example you can search web - based on logic (like searching in library catalog), and not like to day - which is just matching words. In other words now you have content, RDF gives you content and metadata (content description). Ontologies are next step which gives you relation between objects and so on. > It's similar to a > relational database in that you put pieces of data into the database and > later search for data. But it's much more ad-hoc than a relational > database. > > Serialization of RDF into XML and the relationship between RDF and the > Semantic Web are distinct concepts from RDF theory. > Semantic Web are based on RDF: One path might be (not only one): RDF -> DAML+OIL -> OIL -> Description Logics further for example FaCT -> ALC and so on. > > This ad-hoc data storage made me think of TinyTables. TinyTables is a > good Zope product that fills the need for simple tables of data, but it > needs attention. What if it got replaced by some Zope product called > "RDFBucket"? An RDFBucket object would let you input data in a variety > of ways, including object introspection, forms, and XML with embedded > RDF. It would let you run queries similar to ZCatalog. Maybe it would > also generate RDF for embedding metadata in web pages. > 1st idea: You can implement RDF almost in any SQL language, and be able to Query rdfs. 2nd idea: Besides any document in ZOPE can be RDF - special tags in html-header. On the other hand Plone uses Dublin Core, so you can easily make RSS (syndication), and RDF. But its limited to documents and basic Plone types. So you can, and Plone uses ZCatalog for searching 3rd idea: I haven't done research on RDF and Zope/Python, yet, but it seams to be a good idea to do something like "RDFBucket" especialy using ZODB (maybe not derivied from TinyTable). I also consider this idea but I would do it more like RDFS - Folder like object with (rdf) properties containing other objects (subclasses). This is about "5" minutes of programing. My consideration are going further - I'm thinking, about further develepment of this idea into OIL, DAML compatibile (restrictions, constraints), but I've to get check also OWL:) > > I'm wondering if I'm thinking in line with RDF theory, or if I've veered > off track. If you're familiar with RDF: What do you think? > > Shane > Hope this gives you some light:) Lukasz ___ Zope-Dev maillist - [EMAIL PROTECTED] http://mail.zope.org/mailman/listinfo/zope-dev ** No cross posts or HTML encoding! ** (Related lists - http://mail.zope.org/mailman/listinfo/zope-announce http://mail.zope.org/mailman/listinfo/zope )
