> I would strongly doubt that count() without a where clause isn’t already highly optimized It's actually not well optimized in PostgreSQL because of MVCC. See

> I would strongly doubt that count() without a where clause isn’t already highly optimized It's actually not well optimized in PostgreSQL because of MVCC. See https://wiki.postgresql.org/wiki/Slow_Counting https://wiki.postgresql.org/wiki/Slow_Counting TL;DR: The fact that multiple transactions can see different states of the data means that there can be no straightforward way for "COUNT(*)" to summarize data across the whole table. PostgreSQL must walk through all rows to determine visibility.