Collection Object

[Ruslan Zasukhin]

On 7/31/06 3:47 PM, "Ruslan Zasukhin" <sunshine at public.kherson.ua> wrote:

>> For case of 2 tables, we put pointer into MANY table. Right?
>> So may be here we also should think in this way..
>> Hmm, in this way hard...
>> 
>> 
>> Well, then it seems you can use only next way
>> 
>> 
>> In TC you make VarChar for example, and store data as:
>> 
>>     121355354,1545115,154321354,13564351356,
>> 
>> I.e. You make LIST of records with their OID values.
> 
>>> Yes, it definitely more hard and I don't see the advantage over an
>>> M:M table so farŠ
> 
> Another way:
> 
> So we have 
> 
>     TC - on left side                    Few tables on right side
> 
> To link them we use special table:
> 
>                   --------------------------
>                      intermediate table
>                   --------------------------
>                      RecID_TC   |    OID


Interesting. Main problem in your case that you want that

    LEFT_TC  keep collection of records from SEVERAL tables on right side.

If talk about one table one Right Side than BinaryLink works perfectly.
But you want many tables on right side...


Can you describe scenario of

    * how records will be added/deleted into right tables ?

    * how are NSSet is born?
        is it owner of records in collection? Or just keep them?
        what must happens if I delete NSSet?

        what must happens if I delete record in T2 which is in some set?

    * Let you have records in all tables, what next? What operations?
        search? Iteration? Navigation? Else? How ?


May be exists sense try develop IDEAL abstraction that can manage this ?

May be let's look into OO DBMS and ODMG? Although as I remember they support
collections that just keep some kind of general parent class. I.e. They use
advantage of inheritance..


-- 
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]