priv/repo/migrations/20230127143303_rename_index_users_ap_id_coalesce_follower_address_index.exs

@@ -0,0 +1,23 @@
+defmodule Pleroma.Repo.Migrations.RenameIndexUsersApId_COALESCEFollowerAddressIndex do
+  alias Pleroma.Repo
+
+  use Ecto.Migration
+
+  def up do
+    # By default Postgresql first restores the data and then the indexes when dumping and restoring the database.
+    # Restoring index activities_visibility_index took a very long time.
+    # users_ap_id_COALESCE_follower_address_index was later added because having this could speed up the restoration tremendously.
+    # The problem now is that restoration apparently happens in alphabetical order, so this new index wasn't created yet
+    # by the time activities_visibility_index needed it.
+    # There were several work-arounds which included more complex steps during backup/restore.
+    # By renaming this index, it should be restored first and thus activities_visibility_index can make use of it.
+    # This speeds up restoration significantly without requiring more complex or unexpected steps from people.
+    Repo.query!("ALTER INDEX public.\"users_ap_id_COALESCE_follower_address_index\"
+    RENAME TO \"aa_users_ap_id_COALESCE_follower_address_index\";")
+  end
+
+  def down do
+    Repo.query!("ALTER INDEX public.\"aa_users_ap_id_COALESCE_follower_address_index\"
+    RENAME TO \"users_ap_id_COALESCE_follower_address_index\";")
+  end
+end