Re: The wisdom of the object mentors (Was: Searching OO Associations with RDBMS Persistence Models)

From: Bob Badour <bbadour_at_pei.sympatico.ca>
Date: Fri, 02 Jun 2006 14:44:32 GMT
Message-ID: <k9Yfg.16525$A26.381173_at_ursa-nb00s0.nbnet.nb.ca>


Phlip wrote:

> David Cressey wrote:
> 

>>I'm lost with "conceptual distance".
>
> Google "separation of concerns".

Why? One won't discover anything to support your thesis by doing so.

>>Here's a scenario. We look at four modules (out of hundreds) in a large
>>hospital data magement system.
>>
>>One module massages data about health insurance, credit cards, and
>>reimbursement. It is written in Java.
>>A second module exchanges data with the DBMS about health insurance,
>>credit
>>cards, and reimbusement from the . It is written in SQL, with a thin
>>wrapper of Java.
>>A third module exchanges data with the DBMS about clinical histories,
>>patient privacy, and compliance with privacy law. It is written in SQL,
>>with a thin wrapper of Java.
>>A fourth module massages data about clinical histories, patient privacy,
>>and compliance with privacy law. It is written in Java.
>>
>>It sounds from what you've said above as though the "conceptual distance"
>>between modules 2 and 3, and between 1 and 4 is short, while the
>>"conceptual distance" between modules 1 and 2, and between 3 and 4, is
>>long.
>>
>>This makes no sense to me.
>
> All four modules need high-level objects,

High level like relations? Or lower level like object variables?

  and they need persistence, so
> these objects have the right state.

Apparently, you think the low-level object variables are high-level. Do you, honestly, consider them as high-level as relations? If you do, that would explain many of your mistaken beliefs.

[confused ramblings snipped] Received on Fri Jun 02 2006 - 16:44:32 CEST

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