[Info-vax] CRTL and RMS vs SSIO

[Dave Froble]

On 10/14/2021 1:48 PM, Simon Clubley wrote:
> On 2021-10-13, Dave Froble <davef at tsoft-inc.com> wrote:
>> On 10/13/2021 7:23 PM, Arne Vajhøj wrote:
>>> With a relational database in is one SQL statement.
>>>
>>> With an index-sequential file it is writing a conversion program.
>>
>> Not always.  With DAS that utility already exists.  And a bunch more
>> utilities, that work with any DAS file.
>>
>> RMS isn't the only product around ...
>>
>
> Can that utility be used while existing programs which don't need the
> new field continue to run at the same time as you are adding the new
> field ?
>
> If yes, is this still true if you are not allocating the new field
> out of existing dead space in the record and need to extend the
> underlying record to hold the new field ?
>
> IOW, is there any application downtime while you are adding the new
> field in DAS ?
>
> Simon.
>

In a word, yes.

Now, tell me that a database doesn't defer some transactions if it is re-defining a table definition.

In the era that DAS and a whole bunch of software comes from, downtime for maintenance, backups, and such was normal.

Today's software benefits from new capabilities, new requirements, and such.  That is a good thing.

But consider where the new capabilities came from.  Perhaps learning things while using older software?

Arne figured a new conversion program would be required.  Not with a product that anticipated
such conversions, and provided methods to perform them.  Does DAS have limitations?  Damn right it does,
and I seem to recall writing multiple times that if I was designing an application today, I'd most likely
choose a modern RDBMS.  However, I sometimes get the impression, perhaps mistakenly, that some might feel
that every year everything should be re-implemented using new technology, throwing out all the old stuff.
That sort of irritates me.  After all, it was the old stuff that got us to where we are today, including
the lessons that caused the development of newer methods.

-- 
David Froble                       Tel: 724-529-0450
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