Re: generic modelling of data models; enforcing constraints dynamically... - Mailing list pgsql-general

From InterRob
Subject Re: generic modelling of data models; enforcing constraints dynamically...
Date
Msg-id 671e36b0909241407k5b66398bqa07909bdbe29d126@mail.gmail.com
Whole thread Raw
In response to Re: generic modelling of data models; enforcing constraints dynamically...  (Sam Mason <sam@samason.me.uk>)
Responses Re: generic modelling of data models; enforcing constraints dynamically...  (Sam Mason <sam@samason.me.uk>)
Re: generic modelling of data models; enforcing constraints dynamically...  (Erik Jones <ejones@engineyard.com>)
List pgsql-general
I guess it IS quite overengineered indeed...

What I'm trying to do is to facilitate different fieldwork methodologies for archaeological research (on project basis); there is no final agreement on data structure and semantics; however, on a meta-level all choices are rational and can be modelled... Infact, all models can be related to each other: that's where the "hybrid" part comes in: I wish to implement the common denominator (90%) and then further extend this, enabing specific data model implementations -- including checks for data integrity.

As soon as that works, it becomes possible to record changes at row-level -- providing access to data-snapshots in time. Furthermore, it becomes possible to build upon this central database automated tools for management and filing of information and different modes of data entry (including webbased)...

The thing is: altering table structures (changes should be limited to adding columns) is required on a ad hoc basis and End User should be able to do so... I guess that requires some over engineering... ?


Rob

2009/9/24 Sam Mason <sam@samason.me.uk>
On Thu, Sep 24, 2009 at 10:33:37PM +0200, InterRob wrote:
> I came to think of another option: putting additional columns (that is:
> addittional to the default set of fields) in xml, in a column that is part
> of row (=object) it belongs to.
> Any body has done so before? Any body has experience with XML schema
> validation within PostgreSQL?

Sorry; but was sounding a little over engineered before, it seems to be
blowing out of proportion now.  By whom and how are these (immensely
complicated) rule sets going to be maintained? how is using XML going to
make this any easier than using the tools native to the database?

If they're validated inside the database then it's going to be done by a
DB admin anyway, or am I missing something?  If they're done by the DB
admin, isn't it easy to just use the tools they're used to?

--
 Sam  http://samason.me.uk/

--
Sent via pgsql-general mailing list (pgsql-general@postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-general

pgsql-general by date:

Previous
From: Sam Mason
Date:
Subject: Re: generic modelling of data models; enforcing constraints dynamically...
Next
From: Tom Lane
Date:
Subject: Re: v8.1 pgbench ERRORs