[Info-vax] VMS Software: New US Mailing Address

[Arne Vajhøj]

On 10/12/2022 6:58 PM, Bill Gunshannon wrote:
> On 10/12/22 17:33, Arne Vajhøj wrote:
>> On 10/12/2022 4:20 PM, Bill Gunshannon wrote:
>>> Using a compatibility layer and trying to make PostGres look like
>>> RDB (or Oracle) would be a major mistake. Better to bite the bullet
>>> and move into the current century.
>>
>> It is a tradeoff.
>>
>> There are benefits from doing things the standard way instead of
>> doing it the compatibility way.
>>
>> But there are also huge cost of changing the client applications.
> 
> Maybe and maybe not as much as you think.  Granted, most of my
> experience doing it has been with COBOL but I have been able to
> take programs using databases from other systems and moved them
> quite easily.  I would  love to have someone send me a COBOL
> program that uses RDB just for a look-see.

Cobol embedded SQL is probably one of the more portable. But it is
not supported by PostgreSQL project itself.

An extremely simple Cobol embedded SQL to Rdb example:
   https://www.vajhoej.dk/arne/articles/vmsdb.html#rdb_cob_emb

>>>                                  I have never used RDB (I have
>>> used Oracle) but I assume it supports EXEC SQL and the usual SQL
>>> syntax.  If so, moving could be fairly easy.  If not, could be a
>>> problem.  Of course, probably also depends on the language being used.
>>
>> It will indeed depend on the language and the API used.
>>
>> embedded SQL/C => relative easy (PgSQL has precompiler)
>>
>> embedded SQL/Cobol => maybe easy (an open source precompiler 
>> supposedly exist and work)
>>
>> embedded SQL/Pascal, Fortran ... => major rewrite (precompilers are 
>> not available)
> 
> Yes, but I would imagine given the two existing pre-compilers coming
> up with one for Pascal and Fortran would not be all that difficult.

Maybe not. But so far it has not been done.

> Of course, I would wonder how many people there are still using Pascal
> and Fortran for database applications.  :-)

VMS applications are done in many languages. I would expect some
to exist. VSI seems to expect that as well since SQLRelay come
with API examples in Fortram, Pascal and Basic (besides Cobol, C
and C++).

Arne