Re: How to create a DBMS from scratch?

Emmett wrote:
>Sometime in 1996 or 1997 I recall reading in the Wall Street Journal
>where Oxford .. Oxford something ... some gigantic health insurer
>based in Chicago (I think) migrated away from Pick to a
>relational database (I think Oracle).
>
>It was a total disaster precisely because so much of what was
>done in Pick couldn't be done at all using a relational DB.
>
>Since Oxford was growing outrageously quickly they weren't
>able to bill all their patients. It was common for doctors to wait
>six to eight months for payment.
>
>Oxford wasn't able to bill many of it's patients because
>their database system was hosed.
>
>The entired deal parciptated some big event - like Oxford going
>out of business completely - or getting in trouble for having
>merged with some other insurer and messing things up.
>
>Great story. I wish I could remember it better.

Me too, because the details matter here. It is trivial to find a mapping from the Pick data model to a relational model, but the question is what your requirements are. So it all hinges upon the question how good your system analysts, who have to define this mapping, are. If these people don't know their job you can even get into the same problems when moving from an Excel-based application to a database-based application. That doesn't prove that Excel is a better database.

• Jan Hidders