How to force AR belongs_to include option to eager load?

Rails
1

Hello

I have two classes

class SolarSystem < ActiveRecord::Base
has_many :fow_ss_entries, :dependent => :delete_all

class FowSsEntry < ActiveRecord::Base
belongs_to :galaxy
belongs_to :solar_system
belongs_to :player

named_scope :for, Proc.new { |galaxy, player|
galaxy = galaxy.id if galaxy.is_a? Galaxy
player = player.id if player.is_a? Player

{
  :conditions => {:galaxy_id => galaxy, :player_id => player},
  :include => :solar_system
}

}

Now the evil thing is, that even thou’ :include is specified, it does
nothing. New AR eager loading resorts to doing n+1 sql queries in
FowSsEntry.for(1,1).each { |fse| fse.solar_system }

How do I force it into joining my table, without impacting my SQL
performance?

2

On Nov 2, 10:56 pm, Artûras Ðlajus [email protected]
wrote:

Now the evil thing is, that even thou’ :include is specified, it does
nothing. New AR eager loading resorts to doing n+1 sql queries in
FowSsEntry.for(1,1).each { |fse| fse.solar_system }

How do I force it into joining my table, without impacting my SQL
performance?

Is the issue the fact that :include does not always trigger a join
based strategy ? What are the actual sql queries you see?

Fred

3

Frederick C. wrote:

On Nov 2, 10:56�pm, Art�ras �lajus [email protected]
wrote:

Now the evil thing is, that even thou’ :include is specified, it does
nothing. New AR eager loading resorts to doing n+1 sql queries in
FowSsEntry.for(1,1).each { |fse| fse.solar_system }

How do I force it into joining my table, without impacting my SQL
performance?

Is the issue the fact that :include does not always trigger a join
based strategy ? What are the actual sql queries you see?
Yes.

I see this:
[2009-11-03 00:35:26|main|debug] FowSsEntry Load (0.0ms) SELECT * FROM
fow_ss_entries WHERE (fow_ss_entries.galaxy_id = 1 AND
fow_ss_entries.player_id = 1)
[2009-11-03 00:35:26|main|debug] SolarSystem Load (0.0ms) SELECT * FROM
solar_systems WHERE (solar_systems.id = 57)
[2009-11-03 00:35:26|main|debug] SolarSystem Load (0.0ms) SELECT * FROM
solar_systems WHERE (solar_systems.id = 157)
[2009-11-03 00:35:26|main|debug] SolarSystem Load (0.0ms) SELECT * FROM
solar_systems WHERE (solar_systems.id = 313)
[2009-11-03 00:35:26|main|debug] SolarSystem Load (0.0ms) SELECT * FROM
solar_systems WHERE (solar_systems.id = 314)

Which is kind of bad ;(

4

Is there a method for forcing a join-based strategy?

On Nov 3, 2:09 am, Artûras Ðlajus [email protected]