Fix: アカウント一覧、カスタム絵文字一覧画面を高速化 (#585)

* Change: アカウント一覧、カスタム絵文字一覧でCOUNTを発行しないように

* Add index

* Fix test

db/post_migrate/20240217215134_improve_remote_pending_accounts_index.rb

@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+class ImproveRemotePendingAccountsIndex < ActiveRecord::Migration[7.1]
+  disable_ddl_transaction!
+
+  def change
+    remove_index :accounts, :remote_pending, unique: false, algorithm: :concurrently
+
+    add_index :accounts, :id, name: 'index_remote_pending_users', unique: false, algorithm: :concurrently, where: 'domain IS NOT NULL AND remote_pending AND suspended_at IS NOT NULL'
+  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_02_17_093511) do
+ActiveRecord::Schema[7.1].define(version: 2024_02_17_215134) do
   # These are extensions that must be enabled in order to support this database
   enable_extension "plpgsql"
 
@@ -198,8 +198,8 @@ ActiveRecord::Schema[7.1].define(version: 2024_02_17_093511) do
     t.index "(((setweight(to_tsvector('simple'::regconfig, (display_name)::text), 'A'::\"char\") || setweight(to_tsvector('simple'::regconfig, (username)::text), 'B'::\"char\")) || setweight(to_tsvector('simple'::regconfig, (COALESCE(domain, ''::character varying))::text), 'C'::\"char\")))", name: "search_index", using: :gin
     t.index "lower((username)::text), COALESCE(lower((domain)::text), ''::text)", name: "index_accounts_on_username_and_domain_lower", unique: true
     t.index ["domain", "id"], name: "index_accounts_on_domain_and_id"
+    t.index ["id"], name: "index_accounts_on_id", where: "((domain IS NOT NULL) AND remote_pending AND (suspended_at IS NOT NULL))"
     t.index ["moved_to_account_id"], name: "index_accounts_on_moved_to_account_id", where: "(moved_to_account_id IS NOT NULL)"
-    t.index ["remote_pending"], name: "index_accounts_on_remote_pending"
     t.index ["uri"], name: "index_accounts_on_uri"
     t.index ["url"], name: "index_accounts_on_url", opclass: :text_pattern_ops, where: "(url IS NOT NULL)"
   end