Method default

src/expr/src/relation/func.rs:2337–2345

Returns the output of the aggregation function when applied on an empty input relation.

(&self)

    /// Returns the output of the aggregation function when applied on an empty
    /// input relation.
    pub fn default(&self) -> Datum<'static> {
        match self {
            AggregateFunc::Count => Datum::Int64(0),
            AggregateFunc::Any => Datum::False,
            AggregateFunc::All => Datum::True,
            AggregateFunc::Dummy => Datum::Dummy,
            _ => Datum::Null,
        }
    }

    /// Returns a datum whose inclusion in the aggregation will not change its
    /// result.