bookmarks in separate table

priv/repo/migrations/20190413082658_create_bookmarks.exs

@@ -0,0 +1,14 @@
+defmodule Pleroma.Repo.Migrations.CreateBookmarks do
+  use Ecto.Migration
+
+  def change do
+    create table(:bookmarks) do
+      add(:user_id, references(:users, type: :uuid, on_delete: :delete_all))
+      add(:activity_id, references(:activities, type: :uuid, on_delete: :delete_all))
+
+      timestamps()
+    end
+
+    create(unique_index(:bookmarks, [:user_id, :activity_id]))
+  end
+end