Swap Ministers Index GraphQL #joins for #includes

Because, despite looking very similar (to me), of these two methods, ActiveRecord only treats #includes as eagerloading. (For anybody not familiar, this results in lazy-loading, i.e. separate database queries later on for any associations that are accessed in our code.) With my local data, this reduced the number of database queries made in order to serve the Ministers Index page from 1144 down to 280.
alphagov · Dec 16, 2024 · a6d02a4 · a6d02a4
1 parent 358325e
commit a6d02a4
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Showing 2 changed files with 2 additions and 2 deletions.
diff --git a/app/graphql/types/base_object.rb b/app/graphql/types/base_object.rb
@@ -12,7 +12,7 @@ def self.links_field(field_name_and_link_type, graphql_field_type)
       define_method(field_name_and_link_type.to_sym) do
         Edition
           .live
-          .joins(document: { reverse_links: :link_set })
+          .includes(document: { reverse_links: :link_set })
           .where(
             document: { locale: "en" },
             link_set: { content_id: object.content_id },

diff --git a/app/graphql/types/ministers_index_type.rb b/app/graphql/types/ministers_index_type.rb
@@ -61,7 +61,7 @@ class MinistersIndexPersonLinks < Types::BaseObject
         def role_appointments
           Edition
             .live
-            .joins(
+            .includes(
               document: {
                 reverse_links: { # role -> role_appointment
                   link_set: {