Rails - May 2005 - ActiveRecord - Eager updates causing prerformance problems

Hi all,

I have a somewhat simple db structure with Meal and MealPlans and a 
has_and_belongs_to many between the two..

For some reason whenever I update the assocation  (the list of meals that 
belong to a particular meal plan), it updates each and every meal!!!

So my MealPlan model has has_and_belongs_to_many :meal
The meals don''t specify anything regarding the meal_plans..

And I update by calling @meal_plan.meal.clear and then re-adding all the meals 
I would like to associate (ie: @meal_plan.meal << Meal.find_by_name( yada
) )
Then I call @meal_plan.save

Is there a way to limit the aggresiveness of the saving??

Thanks in advance!!

Just bumping my own message thread.. hoping to get some help here :(

To restate my problem using more generic entities... If you have cars and 
people, and a mapping table to define associations between the people and 
cars.. Adding a car to person and saving the person should NOT result in the 
car itself being updated.. but that is the behavior I am seeing.

Is there any way to limit the "eager assocation saving"??

Thanks in advance

On Tuesday 24 May 2005 13:06, Luke Galea wrote:
> Hi all,
>
> I have a somewhat simple db structure with Meal and MealPlans and a
> has_and_belongs_to many between the two..
>
> For some reason whenever I update the assocation  (the list of meals that
> belong to a particular meal plan), it updates each and every meal!!!
>
> So my MealPlan model has has_and_belongs_to_many :meal
> The meals don''t specify anything regarding the meal_plans..
>
> And I update by calling @meal_plan.meal.clear and then re-adding all the
> meals I would like to associate (ie: @meal_plan.meal <<
Meal.find_by_name(
> yada ) ) Then I call @meal_plan.save
>
> Is there a way to limit the aggresiveness of the saving??
>
> Thanks in advance!!
>
> _______________________________________________
> Rails mailing list
> Rails-1W37MKcQCpIf0INCOvqR/iCwEArCW2h5@public.gmane.org
> http://lists.rubyonrails.org/mailman/listinfo/rails

> Is there any way to limit the "eager assocation saving"??
Have a look at this ticket:

http://dev.rubyonrails.com/ticket/1343

Seems to fix what you''re talking about. Give it a try and post
feedback to trac on how it works for you.

-d.

On 5/26/05, Luke Galea <lgalea-vvW6YJTQFGvMohDmgNdYFA@public.gmane.org>
wrote:
> Just bumping my own message thread.. hoping to get some help here :(
> 
> To restate my problem using more generic entities... If you have cars and
> people, and a mapping table to define associations between the people and
> cars.. Adding a car to person and saving the person should NOT result in
the
> car itself being updated.. but that is the behavior I am seeing.
> 
> Is there any way to limit the "eager assocation saving"??
Just curious, you titled this thread "Performance Problems".  Are the
addtional and seemingly unecessary SQL statement(s) actually a
problem?  Or are they a theoretical problem?
 
> On Tuesday 24 May 2005 13:06, Luke Galea wrote:
> > Hi all,
> >
> > I have a somewhat simple db structure with Meal and MealPlans and a
> > has_and_belongs_to many between the two..
> >
> > For some reason whenever I update the assocation  (the list of meals
that
> > belong to a particular meal plan), it updates each and every meal!!!
> >
> > So my MealPlan model has has_and_belongs_to_many :meal
> > The meals don''t specify anything regarding the meal_plans..
> >
> > And I update by calling @meal_plan.meal.clear and then re-adding all
the
> > meals I would like to associate (ie: @meal_plan.meal <<
Meal.find_by_name(
> > yada ) ) Then I call @meal_plan.save
> >
> > Is there a way to limit the aggresiveness of the saving??
> >
> > Thanks in advance!!
> >
> > _______________________________________________
> > Rails mailing list
> > Rails-1W37MKcQCpIf0INCOvqR/iCwEArCW2h5@public.gmane.org
> > http://lists.rubyonrails.org/mailman/listinfo/rails
> _______________________________________________
> Rails mailing list
> Rails-1W37MKcQCpIf0INCOvqR/iCwEArCW2h5@public.gmane.org
> http://lists.rubyonrails.org/mailman/listinfo/rails
>

> Just curious, you titled this thread "Performance Problems".  Are
the
> addtional and seemingly unecessary SQL statement(s) actually a
> problem?  Or are they a theoretical problem?
When I am running in production mode with the db on the same machine as the 
app, it''s all good..

But when I develop with the db on a seperate machine and have the app running 
on my laptop connected wirelessly.. well: performance problems are 
exaggerated.

I like developing like that though because it lets me catch those types of 
problems in the development stage rather than after the app is in heavy use 
and the number of rows has increased to the point where we start hitting that 
limit.

Seems to me you''re just running into network latency there (and/or
bandwidth issues with large datasets), no?

On 5/26/05, Luke Galea <lgalea-vvW6YJTQFGvMohDmgNdYFA@public.gmane.org>
wrote:
> > Just curious, you titled this thread "Performance Problems".
Are the
> > addtional and seemingly unecessary SQL statement(s) actually a
> > problem?  Or are they a theoretical problem?
> 
> When I am running in production mode with the db on the same machine as the
> app, it''s all good..
> 
> But when I develop with the db on a seperate machine and have the app
running
> on my laptop connected wirelessly.. well: performance problems are
> exaggerated.
> 
> I like developing like that though because it lets me catch those types of
> problems in the development stage rather than after the app is in heavy use
> and the number of rows has increased to the point where we start hitting
that
> limit.
> _______________________________________________
> Rails mailing list
> Rails-1W37MKcQCpIf0INCOvqR/iCwEArCW2h5@public.gmane.org
> http://lists.rubyonrails.org/mailman/listinfo/rails
>