OASIS Mailing List ArchivesView the OASIS mailing list archive below
or browse/search using MarkMail.

 


Help: OASIS Mailing Lists Help | MarkMail Help

xdi message

[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]


Subject: Re: [xdi] Minutes: XDI TC Telecon Thursday 1:00-2:30PM PT 2012-01-12


Oh, yes that document! (Thanks Markus!)

The original idea was to merge patterns and constraints (e.g., the FROM and the WHERE clause in SeRQL, http://www.openrdf.org/doc/sesame/users/ch06.html) into one single xdi graph, allowing this latter to contain logical expressions.

About cross referencing the subject:

http://lists.oasis-open.org/archives/xdi/200803/msg00071.html

this was raised from the ambiguity about the order of evaluation of subsegments. In a longstanding old thread ("associativity of $has") I've always supported the idea that the composition operator is left associative (with "left associative" intended as reported here: http://en.wikipedia.org/wiki/Operator_associativity) - and I've still this position (I know Drummond has a different one).

In Markus' original example however the problem was that +phone+home is not a composition, rather it is a specialization (should be +homephone, with somewhere else stated that +homephone is a subproperty of +phone). Model it as a composition result in the ambiguity problem Markus had outlined.

Best Regards,
Giovanni

Def. Quota Markus Sabadello <markus.sabadello@xdi.org>:

I think this document is what I used back then as a basis, plus a few
e-mail threads

http://www.oasis-open.org/committees/download.php/27547/Draft-Contrib-OASIS-XDI-dollar-words-v03.pdf


http://lists.oasis-open.org/archives/xdi/200804/msg00000.html
http://lists.oasis-open.org/archives/xdi/200804/msg00016.html
http://lists.oasis-open.org/archives/xdi/200803/msg00071.html
...

Markus

On Thu, Jan 12, 2012 at 11:56 PM, Drummond Reed <drummond.reed@xdi.org>wrote:

Following are the minutes of the unofficial telecon of the XDI TC at:

Date:  Thursday, 12 January 2012 USA
Time:  1:00PM - 2:30PM Pacific Time (21:00-22:30 UTC)

ATTENDING

Mike Schwartz
Giovanni Bartolomeo
Markus Sabadello
Drummond Reed
Joseph Boyle

REGRETS

Bill Barnhill


THE IDEARPAD LINK FOR TODAY IS:
     http://piratepad.net/3GsPcga5is


1) IDTRUST BUDGET

Great news - the budget request for $5K for interop testing of an XDI
client operating against two XDI servers was approved! Dee Schur has sent a
contract to Markus to review and will have a call with him to go over it.

We discussed the configuration that we would use for it. Markus and Mike
will coordinate the details.

# MARKUS AND MIKE will work out a plan for executing and keep the TC
appraised of progress.


2) OPEN SOURCE PROJECT UPDATES

Mike said that the OpenXDI Project released version .2, and is now working
on the front end needed by MIT. Work now will go into OxAuth.

The next improvements on OxServer will be optimizations on search, plus
work on the OGM (Object Graph Mapping) tool.

Markus said he is beginning work on changes to the Project Danube code
base, and will have more to update next week.


3) LINKED DATA UPDATE

Giovanni said that Linked Data is becoming the defacto standard for
sharing data, and governments are starting to look at it as the standard
for publishing data. He said the Italian Government (after the US, UK and
French Governments), for example, is exploring it now.

Giovanni believes that XDI should be 100% compatible with Linked Data. The
key question that he would like to have researchers explore is defining
what XDI can add to Linked Data. The first point of addition is the ability
to address single nodes inside the graph. The second point is control of
data sharing using link contracts.

Giovanni explained that Linked Data implementers approach the problem of
identification from a different perspective. For example, two different RDF
graphs from two different authorities may use different URIs to represent
the same entity. What is emerging now is the pattern of using hubs to share
URIs that represent a specific entity (including a concept, such as an
ontology definition, or a place, or a product, etc.)

If this trend continues, of referencing/sharing a single "very popular
URI", then Giovanni believes we can map to that URI from an XRI using
either (or both):

   - A cross-reference


   - A short-form XRI, which would provide a single short-form
   "canonical" identifier for the entity.


Giovanni feels that if we take this approach, we can help solve the
problem of disambiguating attributes assigned to the same entity
(identified by a popular URI/XRI) in two different contexts from two
different RDF authoritities. The solution is to make each set of attributes
relative to each of the two authorities using the contextual capability of
XDI.

Giovanni is currently working using statistical techniques to analyze part
of the Linked Data cloud (which is up to 32 billion Linked Data triples) to
identify what appear to be the same entity in different contexts. Once
these are identified, then the XRI can be assigned that would become the
canonical identifier for that resource.

Using this approach -- this XDI dictionary "hub" that establishes the
equivalence of different URIs -- software that uses the hub can do the
mapping across RDF graphs, and then the next step is that the data
publishers can start using longer URIs that incorporate XRIs into their
URIs - making them longer but also embedding the XRI identifier in such a
way that the equivalence can be recognized by processing agents.

Mike pointed out that by creating URI "hubs", the Linked Data community is
already starting to add a data abstraction layer and create canonical
identifiers. Giovanni agreed and said that because this is happening, it
sets up the business case for them to start to use what is specified in the
XRI 3.0 spec, which is to use a concrete http: or https: URI to identify
the provenance of the RDF graph bound to an XRI to identify the entity.
That is a very elegant solution that provides a bridge between the RDF
Linked Data world and the XDI world.

# GIOVANNI will work out a roadmap for how he sees this unfolding, and
then post an update.


4) AUTO-INCREMENT

Mike sent this message to the list:

   http://lists.oasis-open.org/archives/xdi/201201/msg00006.html

He explained that the use case is very common where you need the server to
add the next available i-number for identifying an node.

Drummond and Markus immediately recognized this pattern as something they
had to deal with in a Higgins-related project several years ago. The
solution that we developed was to send the server a $add operation with a
variable in the XRI for the XDI object. The server would see the variable
and then replace it and return the value to the client.

Here is what we agreed on the call, to use variables:

<$sender>/$add/(=schwartz/()/($1))<http://piratepad.net/ep/search?query=schwartz/%28%29/%28$1%29%29>
<$sender>/$add/(=schwartz/()/($2))<http://piratepad.net/ep/search?query=schwartz/%28%29/%28$2%29%29>
<$sender>/$add/(=schwartz($1)/()/+friends)<http://piratepad.net/ep/search?query=schwartz%28$1%29/%28%29/+friends%29>
<$sender>/$add/(=schwartz($2)/()/+friends)<http://piratepad.net/ep/search?query=schwartz%28$2%29/%28%29/+friends%29>

The server would assign the next available unordered index and returns it
in the response to the client.


5) PROPOSALS FOR OPTIMIZING $GET - XDI QUERIES

Continuation of last week's discussion. See:

  http://ox.gluu.org/doku.php?id <http://ox.gluu.org/doku.php?id=xdi:get>
=xdi:get <http://ox.gluu.org/doku.php?id=xdi:get>

Drummond and Markus brought up that a basic query syntax was developed a
few years ago and actually implemented by Markus. Originally developed by
Giovanni and with some patterns suggested by Bill, it was very simple yet
very elegant.

# MARKUS agreed to look up the source documents and help port that syntax
forward to the XDI TC wiki page(s) that Mike is creating for a query syntax.

Mike suggests we also discuss via email to be ready for a live discussion
on next week's call.


6) XDI MESSAGE ORIGINATION SOLUTION

Drummond said that he had added the basic solution as the revised first
line (the "from" line) of the XDI message template:

  http://wiki.oasis-open.org/xdi/XdiMessagePatterns

We ran out of time to discuss it on this call, but Drummond will add more
documentation, and we will discuss it next week.


6) NEXT CALL

Although Drummond will be in Europe, he still hopes to be able to attend
the call, and in any case it will be next week at the regular time.
















----------------------------------------------------------------
Invito da parte dell'Ateneo:
Il tuo futuro e quello della Ricerca Scientifica hanno bisogno del
tuo aiuto. Dona il  5 x mille all'Universita' di Roma Tor Vergata
codice fiscale: 80213750583 http://5x1000.uniroma2.it




[Date Prev] | [Thread Prev] | [Thread Next] | [Date Next] -- [Date Index] | [Thread Index] | [List Home]