cache associated target records hash

1 files changed, 11 insertions, 17 deletions

diff --git a/activerecord/lib/active_record/associations/preloader/association.rb b/activerecord/lib/active_record/associations/preloader/association.rb
index a8edf21bef..ef48e9f174 100644
--- a/activerecord/lib/active_record/associations/preloader/association.rb
+++ b/activerecord/lib/active_record/associations/preloader/association.rb
@@ -16,7 +16,7 @@ module ActiveRecord
           @scope         = nil
           @owners_by_key = nil
           @type_caster   = IDENTITY_CASTER
-          @target_records = nil
+          @associated_records_by_owner = nil
         end
 
         def run
@@ -77,21 +77,9 @@ module ActiveRecord
 
         private
 
-        def lhs_records
-          return @target_records if @target_records
-
-          owners_map = owners_by_key
-          owner_keys = owners_map.keys.compact
-
-          sliced  = owner_keys.each_slice(klass.connection.in_clause_length || owner_keys.size)
-          @target_records = sliced.flat_map { |slice|
-            records = records_for(slice)
-            set_type_caster records, association_key_name
-            records
-          }
-        end
-
         def associated_records_by_owner
+          return @associated_records_by_owner if @associated_records_by_owner
+
           owners_map = owners_by_key
           owner_keys = owners_map.keys.compact
 
@@ -101,8 +89,14 @@ module ActiveRecord
           if klass && owner_keys.any?
             # Some databases impose a limit on the number of ids in a list (in Oracle it's 1000)
             # Make several smaller queries if necessary or make one query if the adapter supports it
+            sliced  = owner_keys.each_slice(klass.connection.in_clause_length || owner_keys.size)
+            records = sliced.flat_map { |slice|
+              records = records_for(slice)
+              set_type_caster records, association_key_name
+              records
+            }
             caster = type_caster
-            lhs_records.each do |record|
+            records.each do |record|
               owner_key = caster.call record[association_key_name]
 
               owners_map[owner_key].each do |owner|
@@ -111,7 +105,7 @@ module ActiveRecord
             end
           end
 
-          records_by_owner
+          @associated_records_by_owner = records_by_owner
         end
 
         def set_type_caster(results, name)