allowedAggregateExpressionType

Specifies whether a query can aggregate a transformed column. This applies to the arguments of both aggregate and window functions. Valid values are:

COLUMNS_ONLY – A query can aggregate only a direct column reference, such as SUM(amount), or a constant. Clean Rooms rejects a query that transforms a column and then aggregates it, such as SUM(amount * 2) or SUM(ROUND(amount)).

ANY_EXPRESSION – A query can aggregate any expression. This includes arithmetic, such as SUM(price * quantity); a cast, such as SUM(CAST(amount AS DECIMAL)); a nested function call, such as SUM(COALESCE(amount, 0)); and a conditional, such as SUM(CASE WHEN region = 'EU' THEN amount ELSE 0 END).