Function attach_grouping_sets

nodedb-sql/src/planner/aggregate.rs:84–121

Attach `grouping_sets` to an existing `SqlPlan::Aggregate` node, or wrap it in a new one when the engine rules returned a non-Aggregate plan.

(
    base_plan: SqlPlan,
    group_by: Vec<SqlExpr>,
    aggregates: Vec<AggregateExpr>,
    having: Vec<Filter>,
    grouping_sets: Vec<Vec<usize>>,
)

/// Attach `grouping_sets` to an existing `SqlPlan::Aggregate` node, or wrap it
/// in a new one when the engine rules returned a non-Aggregate plan.
fn attach_grouping_sets(
    base_plan: SqlPlan,
    group_by: Vec<SqlExpr>,
    aggregates: Vec<AggregateExpr>,
    having: Vec<Filter>,
    grouping_sets: Vec<Vec<usize>>,
) -> SqlPlan {
    match base_plan {
        SqlPlan::Aggregate {
            input,
            limit,
            grouping_sets: _,
            sort_keys,
            ..
        } => SqlPlan::Aggregate {
            input,
            group_by,
            aggregates,
            having,
            limit,
            grouping_sets: Some(grouping_sets),
            sort_keys,
        },
        other => {
            // Engine returned something other than Aggregate (e.g. TimeseriesIngest).
            // Wrap it so grouping sets are not silently dropped.
            SqlPlan::Aggregate {
                input: Box::new(other),
                group_by,
                aggregates,
                having,
                limit: 10000,
                grouping_sets: Some(grouping_sets),
                sort_keys: Vec::new(),
            }
        }
    }
}

/// Extract timeseries-specific parameters from GROUP BY (bucket interval, group columns).
///