Hello,
The type system provided by Spring Data Neo4j has a nearly identical semantics
to Java (and most object oriented languages). The type system employed by
FreeBase is more aligned with description logics --- RDFS/OWL.
For many who live in the world of object oriented programming, being able to do
Graph-Object mapping (like ORM) is nice and that is what Spring Data Neo4j
provides. However, what would be enticing is a general reasoning engine for
which Spring Data Neo4j would be based on --- and various logics being able to
be loaded. In this way, other data semantics can be expressed to allow the
types of things that (for example) the author of "The Coming SQL Collapse"
wrote --- Baysian inference. With Spring Data Neo4j you get SUBLCASS
inheritance, CAN_HAVE properties, and close world reasoning. This is not
conducive to Baysian-based reasoning, evidential reasoning, other forms of
logics (classical and non-classical) ....
For many, it doesn't matter---the world is composed objects and explicit
relations between objects. However, I believe there is a larger space wherein
which graph databases can shine -- and shine brighter than other database
technologies. In this space, the world isn't necessarily object oriented.
"If I gave them what they wanted, I would have bred a faster horse."
- Henry Ford
Take care,
Marko.
http://markorodriguez.com
On Oct 14, 2011, at 10:32 AM, Thad Guidry wrote:
> I should further say after looking more at Spring Data Neo4j ... that it
> allows an easy Type system layer on top of Neo4j. Is that correct ? The
> same kind of Type system that Freebase.com has had always.
>
> In fact, Micheal, I would say even say that with Spring Data Neo4j
> installed, you could almost point users to the Freebase Data modeling style
> guide as a good reference :
> http://wiki.freebase.com/wiki/Data_modeling_style_guide
>
> On Fri, Oct 14, 2011 at 11:26 AM, Thad Guidry <thadgui...@gmail.com> wrote:
>
>> From your quick example, it looks like Spring Data Neo4j is what most folks
>> really expect out of the box with Neo4j. I know I certainly did when I
>> installed Neo4j for the first time, last year. Spring Data seems to meet
>> with my expectation (based on my bottom-up Schema-evolving work on
>> Freebase.com)
>>
>>
>> On Fri, Oct 14, 2011 at 11:15 AM, Michael Hunger <
>> michael.hun...@neotechnology.com> wrote:
>>
>>> With spring data neo4j you are able to use any domain entity with any
>>> node, so it is for instance
>>> possible to project an entity to another when used in a different context.
>>>
>>> Otherwise the Spring Data Neo4j config less invasive and more concise than
>>> the existing model
>>> but uses the same approach behind the scenes (fields are mapped to
>>> properties and relationships - 1:1 or 1:n are mapped to relationships).
>>>
>>> @NodeEntity
>>> class Movie {
>>> String title;
>>> Set<Actor> actors;
>>> }
>>>
>>> a more elaborate example.
>>> @NodeEntity
>>> class Movie {
>>> @GraphId Long id;
>>> @Indexed(fulltext=true, indexName="movies") String title;
>>> @RelatedToVia(type="ACTS_IN", direction=Direction.INCOMING)
>>> Iterable<Role> roles;
>>> Person director;
>>> }
>>>
>>> @RelationshipEntity
>>> class Role {
>>> @Indexed String title;
>>> @StartNode Actor actor;
>>> @EndNode Movie movie;
>>> }
>>>
>>> @NodeEntity
>>> class Actor {
>>> String name;
>>> Gender gender;
>>> Date birthday;
>>> public Role actsIn(Movie movie, String role) {
>>> return relateTo(movie,"ACTS_IN",Role.class).withTitle(role);
>>> }
>>> @RelatedTo(type="ACTS_IN")
>>> Set<Movie> movies;
>>> }
>>>
>>>
>>> Am 14.10.2011 um 16:14 schrieb Thad Guidry:
>>>
>>>> I would suggest breaking down his statement further and fill in the
>>> blanks
>>>> to gain even better insight into his conjecture.
>>>>
>>>> "it‘s basically a bunch of nodes where you just blob your attributes.‘
>>>> Worse than that, to wrap objects around it, you have to have them
>>> explicitly
>>>> incorporate their node class, which is ugly, smelly, violates every law
>>> of
>>>> separation of concerns and logical vs. physical models."
>>>>
>>>>
>>>> "it's" - Neo4j
>>>>
>>>> "to wrap objects around IT" - what is the IT that he is referring to ?
>>>>
>>>> "you have to have THEM explicitly incorporate THEIR node class" - what
>>> is
>>>> THEM / THEIR really mean for Neo4j here ?
>>>>
>>>> "law of separation of concerns" - what and where are we JOINING that
>>> should
>>>> be SEPARATING , is it only the Domain objects ?
>>>>
>>>>
>>>> From outside looking in, I have seen others not complete their Domain
>>> Model
>>>> as needed with Neo4j, and also make it entirely TOO SIMPLE. Why ?
>>> Because
>>>> they might be new to graph databases, or their Domain Model really IS
>>> NOT
>>>> complete yet and they need help from others to assist with putting
>>> together
>>>> an elegant Domain Model to begin with. Being able to easily wire up a
>>>> Domain Model is the primary reason they were attracted to graph
>>> databases in
>>>> the first place !... to build it out without resorting to defining a
>>> rigid
>>>> schema (a SQL table mantra). But many need help in contorting their
>>> Domain
>>>> Model over time. To me, Neo4j is already wide open enough to handle
>>> that
>>>> contortion and the beauty of Neo4j & graph databases in general.
>>>>
>>>> Folks just need better much more detailed Domain Model examples than
>>> what is
>>>> available, that would help incredibly so, since many folks have a
>>> complex
>>>> Domain Model to begin with (they just do not realize it yet) and they
>>> are
>>>> hoping Neo4j will help them quickly wire it up, stretch it out when
>>> needed,
>>>> and analyze the hell out of it when the time comes, and stretch it out
>>> even
>>>> more as they continue to fill it up and expand their Domain Model. A
>>> bottom
>>>> up approach (and I mean really BOTTOM) is the best practice, but it does
>>>> take thought and research in finding where that generic bottom is at. A
>>>> "Friend" - what is a Friend, what attributes does a Friend have ? Which
>>> ones
>>>> do I care about now and can worry about later ? A "Stock Issuing
>>> Company",
>>>> do I need to think of my relationships first for those, or should I
>>> start
>>>> with attributes ? Will those attributes be shared with others ? Do I
>>> care
>>>> about it now at this early beginning of my Domain Model, or can I wait
>>> on
>>>> this ? Should I start with attributes (properties) always, and leave
>>>> relationships alone until the very end, when I build a Domain Model ?
>>> (the
>>>> answer to that last question is YES, because Neo4j actually DOES allow
>>> you
>>>> to)
>>>>
>>>>> He attacks our pattern of building domain models with Neo4j, calling it
>>>>>> "ugly", "smelly" and "in violation of every law of separation of
>>> concerns
>>>>>> and logical vs. physical models". Is he right? My feeling is that he
>>> is
>>>>>> brain washed with too many so called "best practices", but Neo4j has
>>> been
>>>>> my
>>>>>> main model for a long time now, my perspective is likely skewed. I'd
>>> like
>>>>> to
>>>>>> hear your thoughts.
>>>>>
>>>>
>>>> Your main model IS NOT Neo4j. That is your main database that "holds"
>>> your
>>>> Domain Model. And if Neo4j is not really doing this from top to bottom,
>>>> then I would agree with Richard that the Neo4j infrastructure is not in
>>> the
>>>> best place right now and might need more work.
>>>>
>>>> --
>>>> -Thad
>>>> http://www.freebase.com/view/en/thad_guidry
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>>
>>
>>
>> --
>> -Thad
>> http://www.freebase.com/view/en/thad_guidry
>>
>
>
>
> --
> -Thad
> http://www.freebase.com/view/en/thad_guidry
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