Strict Loading Utilizing :n_plus_one_only Mode Does Not Eagerly Load Baby Associations In Rails 7.2.

Rails strict_loading mode is to stop lazy loading of associations.

When the strict_loading mode is used,
the related information should be keen loaded utilizing contains else a ActiveRecord::StrictLoadingViolationError shall be raised.

This mode helps in figuring out
and fixing N+1 question points by making certain that sure associations are loaded eagerly to keep away from efficiency bottlenecks.

class Shopper < ApplicationRecord
  has_many :initiatives
finish

Shopper.strict_loading.first.initiatives 

# raises ActiveRecord::StrictLoadingViolationError

class Shopper < ApplicationRecord
  has_many :initiatives, strict_loading: true
finish

Shopper.first.initiatives

# raises ActiveRecord::StrictLoadingViolationError

Shopper.contains(:initiatives).first.initiatives
  
  Shopper Load (0.7ms)  SELECT "shoppers".* FROM "shoppers" ORDER BY "shoppers"."id" ASC LIMIT $1  [["LIMIT", 1]]
  Undertaking Load (2.4ms)  SELECT "initiatives".* FROM "initiatives" WHERE "initiatives"."client_id" = $1  [["client_id", 1]]

# =>                      
[#<Project:0x00000011133aaa48
  id: 1,
  client_id: 1,
  name: "Miru",
  description: "Time tracking">,
 #<Project:0x0000001111f150b0
  id: 2,
  client_id: 1,
  name: "Azure.com",
  description: "Cloud Computing">
]

Earlier than

Strict loading in :n_plus_one_only mode is particularly designed to deal with efficiency points that may come up when navigating by means of deeply nested associations

It permits direct loading of associations whereas proscribing deeper traversal, stopping potential N+1 question points
and surprises associated to ordering inconsistencies.

shopper = Shopper.discover(1)
shopper.strict_loading!(mode: :n_plus_one_only)
shopper.initiatives.first

# SELECT "initiatives".* FROM "initiatives" WHERE "initiatives"."client_id" = $1  [["client_id", 1]] -- non-deterministic order

The place as navigating by means of deeply nested associations throws error

shopper.initiatives.first.timesheets # raises ActiveRecord::StrictLoadingViolationError

After

Strict loading utilizing :n_plus_one_only doesn’t eagerly load youngster associations.

With this change, youngster associations are not eagerly loaded, to match supposed conduct
and to stop non-deterministic order points brought on by calling strategies like first or final. As first
and final don’t trigger an N+1 by themselves, calling youngster associations will not elevate.

It means associations are eagerly loaded
and youngster associations are lazy loaded.

shopper = Shopper.discover(1)
shopper.strict_loading!(mode: :n_plus_one_only)
shopper.initiatives.first

# SELECT "initiatives".* FROM "initiatives" WHERE "initiatives"."client_id" = $1  [["client_id", 1]] -- non-deterministic order

shopper.initiatives.first.timesheets # not raises error

Abstract

With Strict loading, we will stop lazy loading of associations because it raises ActiveRecord::StrictLoadingViolationError if the related information will not be keen loaded.

However With strict_loading!(mode: :n_plus_one_only), associations are eagerly loaded
and youngster associations are lazy loaded.