Re: The wisdom of the object mentors (Was: Searching OO Associations with RDBMS Persistence Models)
Date: Wed, 31 May 2006 08:16:05 -0500
Message-ID: <2006053108160577923-unclebob_at_objectmentorcom>
On 2006-05-30 05:54:52 -0500, "David Cressey" <dcressey_at_verizon.net> said:
>
> "Alfredo Novoa" <alfredo_novoa_at_hotmail.com> wrote in message
> news:1148940908.338233.159400_at_j73g2000cwa.googlegroups.com...
>
>>> No, a DBMS is a bucket of bits with some low level rules to manage >>> those bits. An OO application provides the beavior that the customer >>> wants to see. We can completely eliminate the DBMS and replace it with >>> another of an entirely different form (non Relational for example) and >>> still have all the business behavior we need. >> >>> The people who sell databases have sold you, and the industry, a >>> misconception: that the database is the heart of the system. This is >>> flawed. The heart of the system is the application code. The database >>> is a detail to be decided at the last possible moment and kept in a >>> position so flexible that it can be swapped out for another at a whim.
>
> I disagree completely with the above, which seems to have been written by
> Robert Martin.
It was.
> The heart of the system is the data.
*One* heart of the system is the data *model*. The technology that stores the data within that model is a detail.
> For 20 years, I believed that the heart of the system was the application
> code. I wrote application code. That's why I believed it. But I've seen
> enough to convince me otherwise in the last 17 years.
>
> Not that I didn't say: "the database". What if we change database vendors?
> Been there, done that.
> What if we rewrite almost all the application code? Been there, done that.
>
> What if we destroy all the data up to this point? Time to update your
> resume, everybody!
Granted, granted. But destroying the data is not the same as isolating the data management mechanism from the data model.
Actually, based on your post, I don't think you disagree completely with mine. At most I think you disagree with the emphasis. My "bucket of bits" statement is extreme because I am often found in the situation of helping teams of developers who start their projects by saying: "OK, we've got Oracle. Now what?"
-- Robert C. Martin (Uncle Bob) | email: unclebob_at_objectmentor.com Object Mentor Inc. | blog: www.butunclebob.com The Agile Transition Experts | web: www.objectmentor.com 800-338-6716 |Received on Wed May 31 2006 - 15:16:05 CEST