akkoma/priv/repo/migrations/20190205114625_create_thread_mutes.exs

defmodule Pleroma.Repo.Migrations.CreateThreadMutes do
  use Ecto.Migration

  def change do
    create_if_not_exists table(:thread_mutes) do
      add :user_id, references(:users, type: :uuid, on_delete: :delete_all)
      add :context, :string
    end

    create_if_not_exists unique_index(:thread_mutes, [:user_id, :context], name: :unique_index)
  end
end