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From Jorg Heymans>
Subject Re: repeater calls row-path method n+1 times
Date Fri, 24 Sep 2004 15:27:09 GMT

Vadim Gritsenko wrote:
> Not to prevent you from tinkering with this code, but a side comment 
> about "hooking up an O/R mapping". I don't think I'd be totally off mark 
>  if I were to say that any respectable O/R mapping will make sure that:
>  * Any obj.get() will pull information from database only once during 
> the life of the transaction, and only in case lazy loading is used

s/will/should/ , and only when configured to do so. It's hibernate i am 
using, for the moment it's setup not to do any caching at all. Note that 
at this point in my app i don't need to write anything back, so there 
are no transactions involved yet.

>  * Any set() won't write anything to database at all till some kind of 
> obj.commit() or is called

> Given these two points, it becomes less important how many times set/get 
> is called. But it does not mean it should not be fixed :)
Well depends, i don't know (yet) what CForms does 12 times with the 
collection it retrieves. If it's a large collection and CForms is doing 
something else besides array reference assigning then it will become 
problematic in terms of performance.

> PS Never worked with OJB / hibernate yet; how do they operate in such 
> situation? IIRC, JDO operates exactly as described above.

It works quite well up until know. I have a huge datamodel to deal with, 
used middlegen to extract the O/R mapping from the database and generate 
the hibernate classes. It saved me heaps of time.


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