Re: generic modelling of data models; enforcing constraints dynamically...

At first glance: brilliant! I was about to implement this key/value thing
with an XML type... I will take a closer look at this, thanks a lot, Oleg!
Tips & tricks to get this going in PostgreSQL?

Rob

2009/9/28 Oleg Bartunov <oleg(at)sai(dot)msu(dot)su>

> Have you considered contrib/hstore to build flexible database scheme ?
>
> Oleg
>
> On Sun, 27 Sep 2009, InterRob wrote:
>
> Dear David, dear Peter, dear all,
>> Peter, I was happy reading your reply right after I opened and read
>> Davids.
>> I do think I am on the right track; it is not a matter of building the
>> one-and-only right schema, not in this case. Archaeology has the same
>> twist
>> as has ethnography, antropology and alike: they work with (what I would
>> call) "narratives" (in fact, in the case of archaeology this seems to me
>> to
>> be an archaeologists monologue...). They try to support their findings
>> with
>> statistics and other means of quatification -- as does this modern,
>> rationalist world require them to do, to be taken seriously as science...
>> I
>> seek to implement all this in a hybrid form; a fusion between the
>> relational
>> and EAV concept.
>>
>> Peter, may I invite you to privately share some more details on the system
>> you are using and the design of it? Did you implement it using PostgreSQL?
>> Looking forward to your reply.
>> (And with respect to your previous message: whom are you actually
>> referring
>> to by the acronym "OPs"?)
>>
>> Cheerz,
>>
>>
>> Rob
>>
>> 2009/9/27 Peter Hunsberger <peter(dot)hunsberger(at)gmail(dot)com>
>>
>> On Sun, Sep 27, 2009 at 2:22 PM, David Fetter <david(at)fetter(dot)org> wrote:
>>>
>>>> On Sun, Sep 27, 2009 at 08:26:27PM +0200, InterRob wrote:
>>>>
>>>>> Dear David, dear all,
>>>>> I very well understand what you are saying...
>>>>>
>>>>
>>>> Clearly you do not. What you are proposing has been tried many, many
>>>> times before, and universally fails.
>>>>
>>>
>>> I've been refraining from jumping on this due to time constraints, but
>>> this statement is silly. We have a system that does almost exactly
>>> what the OP wants although the implementation is slightly different:
>>> we use an EAV like model with strong typing and build set / subset
>>> forests to maintain arbitrary hierarchies of relationships. Our
>>> reasons for doing this are similar to the OPs; it's for research (in
>>> our case medical research). We maintain over 200,000 pieces of end
>>> user generated metadata, describing what would be in a conventional
>>> relational model over 20,000 columns and some 1,000s of tables but the
>>> actual physical model is some 40 tables. Yes, the flip side is, such
>>> a system won't support more than 1,000,000s of transactions per day,
>>> but that's not why you build them.
>>>
>>>
>>>> That your people are failing to get together and agree to a data model
>>>> is not a reason for you to prop up their failure with a technological
>>>> "fix" that you know from the outset can't be made to work.
>>>>
>>>>
>>> Spoken like someone who has always had the luxury of working in areas
>>> with well defined problem domains... I can't tell you the number of
>>> people that told us exactly the same thing when we started on it.
>>> That was 8 years ago. Not only can such systems be built, they can be
>>> made to scale reasonably well. You do need to understand what you are
>>> doing and why: the costs can be high, but when it comes to research,
>>> the benefits can far outweigh the costs.
>>>
>>> --
>>> Peter Hunsberger
>>>
>>>
>>>
>>
> Regards,
> Oleg
> _____________________________________________________________
> Oleg Bartunov, Research Scientist, Head of AstroNet (www.astronet.ru),
> Sternberg Astronomical Institute, Moscow University, Russia
> Internet: oleg(at)sai(dot)msu(dot)su, http://www.sai.msu.su/~megera/
> phone: +007(495)939-16-83, +007(495)939-23-83
>
>