Add actor column to activities.

priv/repo/migrations/20171109091239_add_actor_to_activity.exs

@@ -0,0 +1,24 @@
+defmodule Pleroma.Repo.Migrations.AddActorToActivity do
+  use Ecto.Migration
+
+  @disable_ddl_transaction true
+
+  def up do
+    alter table(:activities) do
+      add :actor, :string
+    end
+
+    execute """
+      update activities set actor = data->>'actor';
+    """
+
+    create index(:activities, [:actor, "id DESC NULLS LAST"], concurrently: true)
+  end
+
+  def down do
+    drop index(:activities, [:actor, "id DESC NULLS LAST"])
+    alter table(:activities) do
+      remove :actor
+    end
+  end
+end