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

Rob,
There are many users of hstore, so you can get support here. Also, someone
is working on the new improved version of hstore, check pgfoundry and
-hackers mailing list.

Oleg
On Mon, 28 Sep 2009, InterRob wrote:

> Second glance: brilliant again! Even support for indexing is available; nice
> job.
> I found the hstore.sql -- that will add type, functions and stuff to my db.
>
> I will give it a serious try!
>
>
> Rob
>
> 2009/9/28 InterRob <rob(dot)marjot(at)gmail(dot)com>
>
>> 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
>>>
>>>
>>
>

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