[remram]

https://www.postgresql.org/docs/14/sql-select.html

    GROUP BY [ ALL | DISTINCT ] grouping_element [, ...]

    grouping_element can be one of:

        ( )
        expression
        ( expression [, ...] )
        ROLLUP ( { expression | ( expression [, ...] ) } [, ...] )
        CUBE ( { expression | ( expression [, ...] ) } [, ...] )
        GROUPING SETS ( grouping_element [, ...] )

You're right about COALESCE of course.