pub fn project(self, outputs: Vec<usize>) -> Self {
        MirRelationExpr::Project {
            input: Box::new(self),
            outputs,
        }
    }
/// Retains only the columns specified by `output`.
Retains only the columns specified by `output`.
Retains only the columns specified by ` output ` .
pub fn project(self, outputs: Vec<usize>) -> Self {
        MirRelationExpr::Project {
            input: Box::new(self),
            outputs,
        }
    }
pub fn project ( self , outputs : Vec < usize > ) -> Self { MirRelationExpr :: Project { input : Box :: new ( self ) , outputs , } }
Retains only the columns specified by `output`.
Retains only the columns specified by ` output ` .
self
outputs
Vec<usize>
self
outputs
Vec<usize>