Function optimize_orders

src/transform/src/join_implementation.rs:1010–1031

Computes the best join orders for each input. If there are N inputs, returns N orders, with the ith input starting the ith order.

(
    equivalences: &[Vec<MirScalarExpr>], // join equivalences: inside a Vec, the exprs are equivalent
    available: &[Vec<Vec<MirScalarExpr>>], // available arrangements per input
    unique_keys: 

//
// If there are N inputs, returns N orders, with the ith input starting the ith order.
fn optimize_orders(
    equivalences: &[Vec<MirScalarExpr>], // join equivalences: inside a Vec, the exprs are equivalent
    available: &[Vec<Vec<MirScalarExpr>>], // available arrangements per input
    unique_keys: &[Vec<Vec<usize>>],     // unique keys per input
    cardinalities: &[Option<usize>],     // cardinalities of input relations
    filters: &[FilterCharacteristics],   // filter characteristics per input
    input_mapper: &JoinInputMapper,      // join helper
    enable_join_prioritize_arranged: bool,
) -> Result<Vec<Vec<(JoinInputCharacteristics, Vec<MirScalarExpr>, usize)>>, TransformError> {
    let mut orderer = Orderer::new(
        equivalences,
        available,
        unique_keys,
        cardinalities,
        filters,
        input_mapper,
        enable_join_prioritize_arranged,
    );
    (0..available.len())
        .map(move |i| orderer.optimize_order_for(i))
        .collect::<Result<Vec<_>, _>>()
}

struct Orderer<'a> {
    inputs: usize,