Fix: ancestor_status_id検索によるDB負荷 (#318)

db/migrate/20231130031209_add_index_on_conversations_ancestor_status_id.rb

@@ -0,0 +1,9 @@
+# frozen_string_literal: true
+
+class AddIndexOnConversationsAncestorStatusId < ActiveRecord::Migration[7.1]
+  disable_ddl_transaction!
+
+  def change
+    add_index :conversations, :ancestor_status_id, where: 'ancestor_status_id IS NOT NULL', algorithm: :concurrently
+  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: 2023_11_15_001356) do
+ActiveRecord::Schema[7.1].define(version: 2023_11_30_031209) do
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
 
@@ -477,6 +477,7 @@ ActiveRecord::Schema[7.1].define(version: 2023_11_15_001356) do
     t.datetime "updated_at", precision: nil, null: false
     t.string "inbox_url"
     t.bigint "ancestor_status_id"
+    t.index ["ancestor_status_id"], name: "index_conversations_on_ancestor_status_id", where: "(ancestor_status_id IS NOT NULL)"
     t.index ["uri"], name: "index_conversations_on_uri", unique: true, opclass: :text_pattern_ops, where: "(uri IS NOT NULL)"
   end