[gigatexal]

Here’s a Redshift oddity that I don’t think is documented:

select sum(y.a), count(y.a) from(select distinct x.a from ( select 1 as a union all select 2 as a union all select 1 as a)x)y

sum | count -----+------- 4 | 3

Sqlite3 returns the correct results of sum of 3 count of 2.

To fix this don’t use subqueries.

[hans_castorp]

Interesting, Postgres does this correctly:

https://dbfiddle.uk/?rdbms=postgres_12&fiddle=dc4ce40bd52695...