pub fn action(&self, relation: &mut MirRelationExpr) -> Result<(), crate::TransformError> {
        if let MirRelationExpr::Reduce {
            input,
            group_key,
            aggregates,
            monotonic,
            expected_group_size,
        } = relation
        {
            // Map expressions can be absorbed into the Reduce at no cost.
            if let MirRelationExpr::Map {
                input: inner,
                scalars,
            } = &mut **input
            {
                let arity = inner.arity();

                // Normalize the scalars to not be self-referential.
                let mut scalars = scalars.clone();
                for index in 0..scalars.len() {
                    let (lower, upper) = scalars.split_at_mut(index);
                    upper[0].visit_mut_post(&mut |e| {
                        if let expr::MirScalarExpr::Column(c) = e {
                            if *c >= arity {
                                *e = lower[*c - arity].clone();
                            }
                        }
                    });
                }
                for key in group_key.iter_mut() {
                    key.visit_mut_post(&mut |e| {
                        if let expr::MirScalarExpr::Column(c) = e {
                            if *c >= arity {
                                *e = scalars[*c - arity].clone();
                            }
                        }
                    });
                }
                for agg in aggregates.iter_mut() {
                    agg.expr.visit_mut_post(&mut |e| {
                        if let expr::MirScalarExpr::Column(c) = e {
                            if *c >= arity {
                                *e = scalars[*c - arity].clone();
                            }
                        }
                    });
                }

                **input = inner.take_dangerous()
            }
            if let MirRelationExpr::Join {
                inputs,
                equivalences,
                implementation: _,
            } = &mut **input
            {
                if let Some(new_relation_expr) = try_push_reduce_through_join(
                    inputs,
                    equivalences,
                    group_key,
                    aggregates,
                    *monotonic,
                    *expected_group_size,
                ) {
                    *relation = new_relation_expr;
                }
            }
        }
        Ok(())
    }
/// Pushes Reduce operators toward sources.
///
/// A join can be thought of as a multigraph where vertices are inputs and
/// edges are join constraints. After removing constraints containing a
/// GroupBy, the reduce will be pushed down to all connected components. If
/// there is only one connected component, this method is a no-op.
Pushes Reduce operators toward sources.
A join can be thought of as a multigraph where vertices are inputs and
edges are join constraints. After removing constraints containing a
GroupBy, the reduce will be pushed down to all connected components. If
there is only one connected component, this method is a no-op.
Pushes Reduce operators toward sources . A join can be thought of as a multigraph where vertices are inputs and edges are join constraints . After removing constraints containing a GroupBy the reduce will be pushed down to all connected components . If there is only one connected component this method is a no - op .
pub fn action(&self, relation: &mut MirRelationExpr) -> Result<(), crate::TransformError> {
        if let MirRelationExpr::Reduce {
            input,
            group_key,
            aggregates,
            monotonic,
            expected_group_size,
        } = relation
        {
            // Map expressions can be absorbed into the Reduce at no cost.
            if let MirRelationExpr::Map {
                input: inner,
                scalars,
            } = &mut **input
            {
                let arity = inner.arity();
                // Normalize the scalars to not be self-referential.
                let mut scalars = scalars.clone();
                for index in 0..scalars.len() {
                    let (lower, upper) = scalars.split_at_mut(index);
                    upper[0].visit_mut_post(&mut |e| {
                        if let expr::MirScalarExpr::Column(c) = e {
                            if *c >= arity {
                                *e = lower[*c - arity].clone();
                            }
                        }
                    });
                }
                for key in group_key.iter_mut() {
                    key.visit_mut_post(&mut |e| {
                        if let expr::MirScalarExpr::Column(c) = e {
                            if *c >= arity {
                                *e = scalars[*c - arity].clone();
                            }
                        }
                    });
                }
                for agg in aggregates.iter_mut() {
                    agg.expr.visit_mut_post(&mut |e| {
                        if let expr::MirScalarExpr::Column(c) = e {
                            if *c >= arity {
                                *e = scalars[*c - arity].clone();
                            }
                        }
                    });
                }
                **input = inner.take_dangerous()
            }
            if let MirRelationExpr::Join {
                inputs,
                equivalences,
                implementation: _,
            } = &mut **input
            {
                if let Some(new_relation_expr) = try_push_reduce_through_join(
                    inputs,
                    equivalences,
                    group_key,
                    aggregates,
                    *monotonic,
                    *expected_group_size,
                ) {
                    *relation = new_relation_expr;
                }
            }
        }
        Ok(())
    }
pub fn action ( & self , relation : & mut MirRelationExpr ) -> Result < ( ) , crate :: TransformError > { if let MirRelationExpr :: Reduce { input , group_key , aggregates , monotonic , expected_group_size , } = relation { // Map expressions can be absorbed into the Reduce at no cost. if let MirRelationExpr :: Map { input : inner , scalars , } = & mut * * input { let arity = inner . arity ( ) ; // Normalize the scalars to not be self-referential. let mut scalars = scalars . clone ( ) ; for index in 0 .. scalars . len ( ) { let ( lower , upper ) = scalars . split_at_mut ( index ) ; upper [ 0 ] . visit_mut_post ( & mut | e | { if let expr :: MirScalarExpr :: Column ( c ) = e { if * c >= arity { * e = lower [ * c - arity ] . clone ( ) ; } } } ) ; } for key in group_key . iter_mut ( ) { key . visit_mut_post ( & mut | e | { if let expr :: MirScalarExpr :: Column ( c ) = e { if * c >= arity { * e = scalars [ * c - arity ] . clone ( ) ; } } } ) ; } for agg in aggregates . iter_mut ( ) { agg . expr . visit_mut_post ( & mut | e | { if let expr :: MirScalarExpr :: Column ( c ) = e { if * c >= arity { * e = scalars [ * c - arity ] . clone ( ) ; } } } ) ; } * * input = inner . take_dangerous ( ) } if let MirRelationExpr :: Join { inputs , equivalences , implementation : _ , } = & mut * * input { if let Some ( new_relation_expr ) = try_push_reduce_through_join ( inputs , equivalences , group_key , aggregates , * monotonic , * expected_group_size , ) { * relation = new_relation_expr ; } } } Ok ( ( ) ) }
Pushes Reduce operators toward sources.
Pushes Reduce operators toward sources .
&self
relation
&mut MirRelationExpr
&self
relation
&mut MirRelationExpr