Trait mz_transform::IndexOracle

pub trait IndexOracle: Debug {
    // Required method
    fn indexes_on(
        &self,
        id: GlobalId
    ) -> Box<dyn Iterator<Item = (GlobalId, &[MirScalarExpr])> + '_>;
}

A trait for a type that can answer questions about what indexes exist.

Required Methods

fn indexes_on( &self, id: GlobalId ) -> Box<dyn Iterator<Item = (GlobalId, &[MirScalarExpr])> + '_>

Returns an iterator over the indexes that exist on the identified collection.

Each index is described by the list of key expressions. If no indexes exist for the identified collection, or if the identified collection is unknown, the returned iterator will be empty.

Implementors

impl IndexOracle for EmptyIndexOracle