Yes, my team had a direct issue with this on Aurora Postgres, at least. This is PG9 but then kept happening all the way into PG12 until we got rid of all but li

Yes, my team had a direct issue with this on Aurora Postgres, at least. This is PG9 but then kept happening all the way into PG12 until we got rid of all but like 5 roles. Above like 4000 roles we experienced a significant lag on every query, sometimes on the order of seconds. At scaled somewhat linearly. I even wrote to Tom Lane and he said that area of Postgres is poorly optimized.