Conversation

db/migrate/20181127130500_identity_id_to_bigint.rb を見てみたら

def up
safety_assured do
change_column_type_concurrently :identities, :id, :bigint
cleanup_concurrent_column_type_change :identities, :id

change_column_type_concurrently :identities, :user_id, :bigint
cleanup_concurrent_column_type_change :identities, :user_id
end
end

だけなんだねえ。トリガつくったりインデックスしなおしたりぜんぶ中の人(誰？)が気にしてくれるのかあ。