Re: Object-relational impedence

Marshall wrote:

> On Mar 19, 6:14 am, Bob Badour <bbad..._at_pei.sympatico.ca> wrote:

>>I am not sure how Eric gets from there to EAV, and I think that's highly >>speculative on Eric's part

> Some of the things Mr. Perryman said led me to believe he was
> discussing an EAV design. When I tried to either verify or dispel
> my impression by reviewing the thread, I wasn't able to either way.
> But I it seems I got a similar impression to Eric's.

A standards body basically defined resource types of the form :

type T
{

     Attr1
     Attr2
     // etc

Attr1 = string
Attr2 = Sequence<SomeNastyRecordType>

There were 100+ resource types, and at least 100+ attr types.

Which types had which attrs, and whether they were mandatory (belonging to all instances of a types) , or optional (present on a per-instance basis) was defined by the standards body (for the perversely-interested, here is one such spec for telecoms call data recording : http://www.itu.int/ITU-T/formal-language/gdmo/database/itu-t/q/q825/1998/q825.html)

This is what the developers were faced with. Store the info for each resource instance (and meta-info to allow the generation/processing of outgoing/incoming messages requesting/retrieving/ setting the attr values) .

Their mandated impl technology : SQL RDBMS.

Regards,
Steven Perryman Received on Wed Mar 19 2008 - 12:15:52 CDT