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

[Jeffrey H. Coffield]

On 01/20/2021 09:06 AM, gérard Calliet wrote:

> 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,...).
>
> Gérard Calliet
>

As I see it, the problems with Cobol redefines and occurs clauses are 
the result of limitations in SQL. We support many Java applications that 
access RMS databases used by large Cobol applications and Java has no 
problems with redefines (each redefine can be extend of a base class or 
a single RMS file can appear as multiple tables with corresponding 
entity classes) or occurs (managed entities have no problem with arrays 
or even HashMaps.) The trick is to have managed entities that are smart 
enough to decode the structures that a SQL query can pass.

My company has developed a JDBC driver for RMS indexed files and a 
persistence layer that achieve this and allow effective joins across 
both RMS and MySQL tables. We are in the process of packaging both the 
driver and persistence layer as open source but are currently uncertain 
of the correct license to use.

Any real solution though is certainly non-trivial and requires some very 
detailed analysis of the particular application.

Jeff Coffield
www.digitalsynerginc.com