app/models/item.rb

@@ -60,23 +60,8 @@ class Item < ApplicationRecord
   }
   scope :occupies, ->(zone_label) {
     zone_ids = Zone.matching_label(zone_label).map(&:id)
-
-    # NOTE: In searches, this query performs much better using a subquery
-    # instead of joins! This is because, in the joins case, filtering by an
-    # `swf_assets` field but sorting by an `items` field causes the query
-    # planner to only be able to use an index for *one* of them. In this case,
-    # MySQL can use the `swf_assets`.`zone_id` index to get the item IDs for
-    # the subquery, then use the `items`.`name` index to sort them.
-    i = arel_table
-    psa = ParentSwfAssetRelationship.arel_table
     sa = SwfAsset.arel_table
-    where(
-      ParentSwfAssetRelationship.joins(:swf_asset).
-        where(sa[:zone_id].in(zone_ids)).
-        where(psa[:parent_type].eq("Item")).
-        where(psa[:parent_id].eq(i[:id])).
-        arel.exists
-    )
+    joins(:swf_assets).where(sa[:zone_id].in(zone_ids)).distinct
   }
   scope :not_occupies, ->(zone_label) {
     zone_ids = Zone.matching_label(zone_label).map(&:id)

db/migrate/20240603181855_add_index_on_name_to_items.rb

@@ -1,5 +0,0 @@
-class AddIndexOnNameToItems < ActiveRecord::Migration[7.1]
-  def change
-    add_index :items, :name
-  end
-end

db/schema.rb

@@ -10,7 +10,7 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema[7.1].define(version: 2024_06_03_181855) do
+ActiveRecord::Schema[7.1].define(version: 2024_05_22_233638) do
   create_table "alt_styles", charset: "utf8mb4", collation: "utf8mb4_unicode_520_ci", force: :cascade do |t|
     t.integer "species_id", null: false
     t.integer "color_id", null: false
@@ -140,7 +140,6 @@ ActiveRecord::Schema[7.1].define(version: 2024_06_03_181855) do
     t.index ["modeling_status_hint", "created_at"], name: "items_modeling_status_hint_and_created_at"
     t.index ["modeling_status_hint", "id"], name: "items_modeling_status_hint_and_id"
     t.index ["modeling_status_hint"], name: "items_modeling_status_hint"
-    t.index ["name"], name: "index_items_on_name"
   end
 
   create_table "login_cookies", id: :integer, charset: "utf8mb4", collation: "utf8mb4_unicode_520_ci", force: :cascade do |t|