Re: relational database

[CRPence <CRPbottle@xxxxxxxxx>]

On 2/8/11 8:12 AM, rob@xxxxxxxxx wrote:
> I really do not think that the S/36, S/34 and their predecessors
> qualify as relational database machines simply because they supported
> a chain by a key instead of just RRN in RPG.
>
> Do you really think the data below is relational?
> A0000100012345Bubba   1313 Mockingbird Lane New York   NY12345
> A00001001XYZ123Steel Coil    ...
>
> <<SNIP>>

  The degree to which the data can be considered relational does not 
correlate directly nor proportionally to the degree to which the DBMS 
provides relational capabilities.

  While those systems may not have provided a RDBMS [e.g. according to 
rules of Codd], at least the S/36 had the capability to define stored 
data to appear relational.  On the S/36 the IDDU [like DDS on the S/38] 
provided the capability to define stored data in a very relational 
manner; i.e. from one scalar entity at each row\column pairing, to 
further normalization available by having data with a common key 
across\into other files that were also appropriately described.  The 
Query/36 [aka QRY/36] provided at least INNER JOIN capability to gather 
the normalized data into a report using the field\column definitions 
from the IDDU that were previously applied to a flat file.

Regards, Chuck