Drop unused indices

This promotes and expands our existing optional migration.
Based on usage statistics from several instances, see:
https://akkoma.dev/AkkomaGang/akkoma/issues/764

activities_hosts is now retained after all since it’s essential
for the "instance" query parameter of *oma’s public timeline to
reliably work in a reasonable amount of time. (Although akkoma-fe has
no support for this feature and apparently barely anyone uses it.)

activities_actor_index was already dropped before in
20221211234352_remove_unused_indices; no need to drop it again.

Birthday indices were introduced in pleroma starting with
20220116183110_add_birthday_to_users which is past the
last common migration 20210416051708.

priv/repo/migrations/20240501190000_drop_unused_indexes.exs

@@ -0,0 +1,64 @@
+defmodule Pleroma.Repo.Migrations.DropUnusedIndexes do
+  use Ecto.Migration
+
+  def up do
+    # Leftovers from a late Pleroma migration (will not be restored on rollback)
+    drop_i(:users, [:show_birthday], :users_show_birthday_index)
+
+    drop_i(
+      :users,
+      ["date_part('month', birthday)", "date_part('day', birthday)"],
+      :users_birthday_month_day_index
+    )
+
+    # Unused
+    drop_i(:activities, ["(data->'cc')"], :activities_cc_index)
+    drop_i(:activities, ["(data->'object'->>'inReplyTo')"], :activities_in_reply_to)
+    drop_i(:activities, ["(data #> '{\"object\",\"likes\"}')"], :activities_likes)
+    drop_i(:activities, ["(data->'to')"], :activities_to_index)
+
+    drop_i(:objects, ["(data->'likes')"], :objects_likes)
+
+    drop_i(:users, [:featured_address], :users_featured_address_index)
+    drop_i(:users, [:following_address], :users_following_address_index)
+    drop_i(:users, [:invisible], :users_invisible_index)
+    drop_i(:users, [:last_status_at], :users_last_status_at_index)
+    drop_i(:users, [:tags], :users_tags_index)
+
+    drop_i(:apps, [:client_id, :client_secret], :apps_client_id_client_secret_index)
+    drop_i(:apps, [:user_id], :apps_user_id_index)
+
+    # Duplicate of primary key index (will not be restored on rollback)
+    drop_i(
+      :user_frontend_setting_profiles,
+      [:user_id, :frontend_name, :profile_name],
+      :user_frontend_setting_profiles_user_id_frontend_name_profile_name_index
+    )
+  end
+
+  def down do
+    create_i(:activities, ["(data->'cc')"], :activities_cc_index, :gin)
+    create_i(:activities, ["(data->'object'->>'inReplyTo')"], :activities_in_reply_to)
+    create_i(:activities, ["(data #> '{\"object\",\"likes\"}')"], :activities_likes, :gin)
+    create_i(:activities, ["(data->'to')"], :activities_to_index, :gin)
+
+    create_i(:objects, ["(data->'likes')"], :objects_likes, :gin)
+
+    create_i(:users, [:featured_address], :users_featured_address_index)
+    create_i(:users, [:following_address], :users_following_address_index)
+    create_i(:users, [:invisible], :users_invisible_index)
+    create_i(:users, [:last_status_at], :users_last_status_at_index)
+    create_i(:users, [:tags], :users_tags_index, :gin)
+
+    create_i(:apps, [:client_id, :client_secret], :apps_client_id_client_secret_index)
+    create_i(:apps, [:user_id], :apps_user_id_index)
+  end
+
+  defp drop_i(table, fields, name) do
+    drop_if_exists(index(table, fields, name: name))
+  end
+
+  defp create_i(table, fields, name, type \\ :btree) do
+    create_if_not_exists(index(table, fields, name: name, using: type))
+  end
+end

priv/repo/optional_migrations/20230422154018_drop_unused_indexes.exs

@@ -1,74 +0,0 @@
-defmodule Pleroma.Repo.Migrations.DropUnusedIndexes do
-  use Ecto.Migration
-
-  @disable_ddl_transaction true
-
-  @disable_migration_lock true
-
-  def up do
-    drop_if_exists(
-      index(:activities, ["(data->>'actor')", "inserted_at desc"], name: :activities_actor_index)
-    )
-
-    drop_if_exists(index(:activities, ["(data->'to')"], name: :activities_to_index))
-
-    drop_if_exists(index(:activities, ["(data->'cc')"], name: :activities_cc_index))
-
-    drop_if_exists(index(:activities, ["(split_part(actor, '/', 3))"], name: :activities_hosts))
-
-    drop_if_exists(
-      index(:activities, ["(data->'object'->>'inReplyTo')"], name: :activities_in_reply_to)
-    )
-
-    drop_if_exists(
-      index(:activities, ["((data #> '{\"object\",\"likes\"}'))"], name: :activities_likes)
-    )
-  end
-
-  def down do
-    create_if_not_exists(
-      index(:activities, ["(data->>'actor')", "inserted_at desc"],
-        name: :activities_actor_index,
-        concurrently: true
-      )
-    )
-
-    create_if_not_exists(
-      index(:activities, ["(data->'to')"],
-        name: :activities_to_index,
-        using: :gin,
-        concurrently: true
-      )
-    )
-
-    create_if_not_exists(
-      index(:activities, ["(data->'cc')"],
-        name: :activities_cc_index,
-        using: :gin,
-        concurrently: true
-      )
-    )
-
-    create_if_not_exists(
-      index(:activities, ["(split_part(actor, '/', 3))"],
-        name: :activities_hosts,
-        concurrently: true
-      )
-    )
-
-    create_if_not_exists(
-      index(:activities, ["(data->'object'->>'inReplyTo')"],
-        name: :activities_in_reply_to,
-        concurrently: true
-      )
-    )
-
-    create_if_not_exists(
-      index(:activities, ["((data #> '{\"object\",\"likes\"}'))"],
-        name: :activities_likes,
-        using: :gin,
-        concurrently: true
-      )
-    )
-  end
-end