[Info-vax] CRTL and RMS vs SSIO

[Dave Froble]

On 10/14/2021 11:27 AM, Arne Vajhøj wrote:
> On 10/13/2021 10:54 PM, Dave Froble wrote:
>> On 10/13/2021 8:31 PM, Arne Vajhøj wrote:
>>> On 10/13/2021 4:53 PM, Dave Froble wrote:
>>>> On 10/13/2021 1:59 PM, Arne Vajhøj wrote:
>>>>> Here is an example of some (Python) code using SQL to
>>>>> join, select, aggregate, sort and limit some data.
>
>>>>> I believe that it would take a lot more code to
>>>>> retrieve data from index-sequential files and
>>>>> do the work on the data.
>>>>
>>>> Not a lot, however the sorting by customer name would entail some
>>>> additional code.
>>>>
>>>> However, reading the order file, doing the selection, look-up customer
>>>> record, and release to record sort, then read back sorted records is
>>>> not "a lot more" code.
>>>
>>> I tried writing it in Pascal using index-sequential files.
>
>> Gee, I'm sure glad I never tried Pascal.
>
> I like Pascal. I know Pascal reasonable well. And Pascal
> got good support for index-sequential files (not like C
> where one would need to use direct RMS calls).
>
> I don't think there is that big potential
> improvements.
>
> Record definitions are a must.
>
> Opening and closing index-sequential files is a must.
>
> Iteration over customers and nested iteration over orders is not
> a must. But I think iterating over orders and updating an
> in-memory customer list will be more code.
>
> If statements for conditions are a must,
>
> 2 loops + 1 if + 3 assignments for sorting can not be done
> easier unless there is a builtin sort function.
>
> I chose to map the 3 tables to 2 index-sequential files
> because I cnsider it realistic to have order and all orderlines
> in a 32K record but unrealistic to have a customer and all orders
> in a 32K record.
>
> Arne

I give up.  I got grass to mow before the dead of winter is upon me.

-- 
David Froble                       Tel: 724-529-0450
Dave Froble Enterprises, Inc.      E-Mail: davef at tsoft-inc.com
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