[Info-vax] Other than Oracle, What MySQL/DBMS options are there for OpenVms?

[Jan-Erik Söderholm]

Den 2019-03-26 kl. 15:30, skrev Arne Vajhøj:
> On 3/26/2019 10:18 AM, Jan-Erik Söderholm wrote:
>> Den 2019-03-26 kl. 03:23, skrev Arne Vajhøj:
>>> On 3/25/2019 9:02 PM, Dave Froble wrote:
>>>> On 3/25/2019 7:31 PM, Arne Vajhøj wrote:
>>>>> Besides that and with the caveat of not knowing much about
>>>>> neither RDB nor PostgreSQL, then I would expect RDB to be
>>>>> lacking some features among what has become common in
>>>>> databases within the last 20 years.
>>>>>
>>>>> If you say that >90% of users do not need those
>>>>> features, then I will say that you are probably right.
>>>>
>>>> That's some rather rash speculation, unless you have some 
>>>> justification.   Just because HP ignored VMS doesn't mean Oracle 
>>>> ignored RDB.
>>>
>>> It is my clear impression that Oracle has provided fine support
>>> for RDB, but I do not think they have evolved the product that much.
>>>
>>> Version number wise RDB has taken 23 years to go from 7.0 to 7.3.
>>>
>>> But we can check. Can someone with extensive RDB knowledge
>>> tell what RDB support from the list below:
>>> * CTE in SQL
>>
>> Seems to be a kind of sub-select. Some sources talked about "self-join"
>> (where a table is joined to itself) but that is no problem in Rdb
>> as fas I know. I probably know too little about "CTE"... :-)
> 
> It is a SQL 99 thingy.
> 
> https://en.wikipedia.org/wiki/Hierarchical_and_recursive_queries_in_SQL#Common_table_expression 
> 
> 
> https://www.essentialsql.com/introduction-common-table-expressions-ctes/
> 
> Lots of databases supports it.
> 
> For reasons unknown to me...

Do check that an come back!

> it is widely used on MS SQLServer but
> more rare in other databases supporting it.
> 
>>> * full text search
>>
>> No, but I do not see the use in typical business applications.
>>
>>> * N data types
>>
>> Is that the NCHAR and similar Unicode types?
> 
> Yes. NCHAR, NVARCHAR and possible NCLOB.
> 
>>                                              Yes, you can specify
>> Unicode or UTF8 as a character set for a column.
>>
>>> * BLOB and CLOB data types (with 1 GB or more max size)
>>
>> Yes. Stored as "segments" with up to 64 Kbyte sizes. No known
>> max size for each BLOB.
>>
>>> * XML and JSON data types
>>
>> Not as specific data types in the tables. But XML available
>> as unload/load file formats.
>>
>>> * geospatial data types
>>
>> Not as specific data types, no.
>>
>>> * stored procedures in other languages than SQL
>>
>> Yes.
>> "User-defined functions allow you to execute subprograms written either
>> in 3GL host languages (such as C or SQL Module language) or in the SQL
>> procedural language."
> 
> So you can write an SP in C/whatever.

Yes and no. "Stored Procedures" are written in SQL (as usual).

*External* procedures/functions can be written in anything, Macro
is just fine. This procedure calls a Macro routine:

create module CPMS_EVENT_SUBM_MODULE

     procedure CPMS_EVENT_SUBM_PROC (
         in    :EVENT
             INTEGER)
     ;
   begin
     declare :stat integer;
     call zvsubmit2('CPMS_QUE',
                    'mk_com:MK_CPMS.com',
                    cast(:event as char(8)),
                    'N',
  Cancel            'Y',
                    'N',
                    'MK',
                    :stat);
   end;

end module;

And the external routine doesn't have to be written at all,
it can be a system service in VMS.


> 
> Does RDB support returning multiple result sets or only a single result set?
> 

You define what paramaters are "in" or "out".
We are not talking about "result sets" like a stream
of records here.

>>> * encrypted connections
>>
>> This is harder. Rdb doesn't have a central database engine like most other
>> DB's has. All database processing is done in the user processes. So local
>> applications never "connects" to Rdb. Remote applications connects through
>> RDBREMOTE or SQL/Services, and that can use any encryption available in
>> your network setup like IPSec, I guess.
> 
> IPSEC is a general network feature.
> 
> Does SQL/Services support encryption between driver and
> itself?

Don't know.

> 
> Arne
> 
>