[ORM]: TYPES

[Ruslan Zasukhin]

On 11/10/07 2:10 PM, "Thorsten Hohage" <thohage at objectmanufactur.com> wrote:

>> And our benefit is:
>>     Valentina Class Way try be as close to Valentina engine as
>> possible.
>>     We not going help to Oracle developers :-)
> 
> Direct reply: When I start using Valentina you told to better use SQL-
> way and not class way, so I build my Framework around the sql-way. Do
> you now really mean that using the Class/API way is a good choice?

Trade-off as always. And better for what ?

You have told about using of VSERVER.
Our answer always is:
    you want VSERVER? So it can be very remote?
    then obviously that MANY small queries will be slower
    of single BIG query? Right?
    
* SQL can do JOIN and other algorithms on SERVER side.

* ORM in contrast try work with Navigational model. Agree?
    you self navigate between objects, loading them when needed.
    but what if millions objects are in game?
    Load them by inet will be huge overhead.

So I have hear about OO DBMS for desktop apps,
    OR around some DB SERVER which is on localhost
    or in the intranet. In this way works EOF, yes?
    EOF is used to access LOCAL DB SERVER to build web site.

In this conditions YES you can use API/Class way and be more effective of
SQL way. Sometimes up to 20 times!!


> -
> 
> I think all this ORM discussion should hat two different aspects. One
> his how to implement a Valentina-ORM in the typical Valentina way (as
> good and as fast as possible) so in this sense we not talk about
> Oracle developers.

Primary task :-)
 
> But the other aspect is to really understand why are things done in a
> way they are and in this case it would help to understand things,
> when not only talking about Valentina developers, but although keep
> the Oracle developers in mind.
 
Learning of existed experience

> My understanding is, that in many cases a good ORM should abstract
> the application-level from the database-level, so that you're able to
> switch between databases stressless.

This is not task of DB VENDOR as WE or Oracle is.

This is dream-task of DB DEVELOPERS. :-)

And it is nothing without SQL Standard. As only one DBMS start have own
features, and you start use them, you have not compatible code.

> A second argument for using ORM is that there are a lot of good and
> well educated OO-developers out there, that are able to do a good
> class design, but only a few 1st class DB designers. But this is NOT
> my argumentation for an ORM.
> 
> But as already written in "common" ORM these days the db is only a
> persistence layer with minimal set of operations.

Thosten,

Why was born idea of OO DBMS?

HISTORY (as I see it :-)

Idea was:

    I am C++/Java developer.
    I want only make C++ classes.
    I do not want even think about DBMS structure, else.

As for me this is way into no where.

Pure OO DBMS developers develop this dbs trying hide DB behind c++ code. And
I can image how NOT EFFECTIVE solutions are. I have hear few developers that
have try develop big projects in OO DBMS


-------
Later vendors of RDBMS also did want add OO features to own products to look
MODERN.

So they have start develop Object-Relational way.


---------
And third wave -- third party vendors which are not DB VENDROS at all, have
start develop different Wrappers/Frameworks around RDBMS

Right?

So this Framework developers need fight with problems of RDBMS model,
implement some algorithm on client-side code.


---------
So ORM and OO developers want give to developer way to work with
    PROGRAMMING LANGUAGE Objects that are stored to disk
        more or less transparently.


Valentina Class way offer little less idea.
    You have tables and field and links as OO CLASES of a Language.
    But 
        * you have Current record in table.
        * you work with SETs of records in this or that table.
        * you navigate between them.

So as for my favor -- it is gold middle between old relational way, and OO
way with not visible db.


-- 
Best regards,

Ruslan Zasukhin
VP Engineering and New Technology
Paradigma Software, Inc

Valentina - Joining Worlds of Information
http://www.paradigmasoft.com

[I feel the need: the need for speed]