akkoma/priv/repo/migrations/20200603122732_add_seen_index_to_chat_message_references.exs

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

  def change do
    create(
      index(:chat_message_references, [:chat_id],
        where: "seen = false",
        name: "unseen_messages_count_index"
      )
    )
  end
end