[ORM] - faulting/collections

[Thorsten Hohage]

Hi Ruslan,

still not able to send mails, but keep answering ;-)

On 2007-10-11, at 10:11, Ruslan Zasukhin wrote:

> On 11/10/07 10:51 AM, "Philip Mötteli" <philip.moetteli at econophone.ch>
> wrote:
>
> Hi Philip,
>
>>> I was told on Cocoa list, that its true that if table T5 has million
>>> records, then system prepare million small RAM objects for future
>>> faulting.
>>>
>>> IMO this is huge overhead.
>>> IMO this is limited way by hardware.
>>>
>>> So is this true that all million objects are prepared?
>>
>> Yes.
>
>> But, objects, that collect other objects are collection objects.
>
> Agree.
>
>> OO
>> is about reusing code. So a programmer shouldn't re-implement
>> collection objects. He should reuse the ones, that are already there.
>
> 100% agree.
>
>> Which means, that the persistence library can also replace them or
>> part of them, so that they use an optimized memory management.
>
> As I have always told -- my believe is:
>
>     db engine must know as many as possible
>     about
>         Tables, Fields, Links, Properties,
>         types of links,
>         methods, inheritance, polymorphism,
>         collections (sets, lists, arrays, ...)
>
>
> When COLLECTIONS will be PART of DATABASE STRUCTURE (!!!)
>     then OR Frameworks will become more and more simple.

yes, but there must be some more things implemented for Valentina5  
except the collections and inheritance and table methods then ;-)


BUT what I want to add about "faulting" and collections in DB and ...

When I need "related" object I perhaps get 1000 faults - this means  
1000 ULongLong number that needed to be transfered to the client.  
When I do it in the db-collection way then probably 1000 invoices are  
transferred and because the positions and reminders are again  
embedded in collections in a row of the invoice table you probably  
transfer them, too. ... Hugh way to wast bandwith and a good example  
to explain novice orm-developers why they should use faults (if the  
ORM did not automatically).

regards

Thorsten Hohage
--
objectmanufactur.com - Hamburg,Germany