Function cross_join_grouping_sets

datafusion/expr/src/utils.rs:165–180

Compute the cross product of two grouping_sets # Example ```text [(A, B), (C, D)], [(E), (F)] -> [(A, B, E), (A, B, F), (C, D, E), (C, D, F)] ``` # Error - [`DataFusionError`]: The number of group_expression in grouping_set exceeds the maximum limit - [`DataFusionError`]: The number of grouping_set in grouping_sets exceeds the maximum limit [`DataFusionError`]: datafusion_common::DataFusionErro

(
    left: &[Vec<T>],
    right: &[Vec<T>],
)

///
/// [`DataFusionError`]: datafusion_common::DataFusionError
fn cross_join_grouping_sets<T: Clone>(
    left: &[Vec<T>],
    right: &[Vec<T>],
) -> Result<Vec<Vec<T>>> {
    let grouping_sets_size = left.len() * right.len();

    check_grouping_sets_size_limit(grouping_sets_size)?;

    let mut result = Vec::with_capacity(grouping_sets_size);
    for le in left {
        for re in right {
            result.push(merge_grouping_set(le, re)?);
        }
    }
    Ok(result)
}

/// Convert multiple grouping expressions into one [`GroupingSet::GroupingSets`],\
/// if the grouping expression does not contain [`Expr::GroupingSet`] or only has one expression,\