[Info-vax] a cool database... as replacement for RMS index-sequential files:: Was: VSI working on alternatives to Oracle Classic database:

[Arne Vajhøj]

On 1/20/2021 1:15 PM, Dave Froble wrote:
> On 1/20/2021 12:06 PM, gérard Calliet wrote:
>> Le 20/01/2021 à 16:40, Arne Vajhøj a écrit :
>>> For an existing VMS application then converting is most likely a good
>>> thing in the long perspective, but since it means changes, then
>>> it needs some analysis on when to do it.
>> My question is just about that.
>>
>> I received a lot of opinions about conversion from applications based on
>> indexed-sequential to relational database which are saying it represents
>> a huge structural transformation, because of the very different
>> philosophies (for example about how to normalize, how to deal with cobol
>> redefines or occurs clauses, etc,...).

>> But perhaps something can be done and there are innovative methods for
>> that. I have not a definitive opinion on that. And because of what you
>> have told, I was a little bit curious.

> Well I do have at least one experience doing such, and what happened was 
> that the old app was used as a guide, the new app was pretty much 
> totally re-written.
> 
> When the basic structure of an app is written around the requirements 
> for database access, and the new database concepts are totally 
> different, there is no possibility of making "small" changes.
> 
> In many cases, it's truly a case of throwing out the baby with the bath 
> water.

If the structure of the app is based on a certain database access
then changing that database access will change the structure
of the app.

No surprise.

That is why it is usually recommended not structuring the
app based on that.

Arne