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

[Jan-Erik Söderholm]

Den 2022-10-12 kl. 23:50, skrev Arne Vajhøj:
> On 10/12/2022 5:45 PM, Jan-Erik Söderholm wrote:
>> Den 2022-10-12 kl. 23:43, skrev Arne Vajhøj:
>>> On 10/12/2022 5:33 PM, 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.
>>>>
>>>>>                                  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)
>>>
>>> Also note that moving to the current century implies
>>> moving from embedded SQL...
>>
>> To what?
> 
> ORM
> standard API (like ODBC, JDBC, DB API 2.0 etc.)
> database specific API (for PGSQL that means libpq*)
> 
> *) libpq is already ported to VMS - https://vmssoftware.com/products/libpq/
> 
> Arne
> 

OK. That works when you have a central database engine/server to
send the request to. There is no such database engine/server in Rdb.

All database "work" is done within the user process. Well, apart from
some management routines, automatic backups and such. But all normal
data manipulations are done in each user process.

So there are no IPC or network latencys to concider.
DLM coordinate accesses/locks and such.