JanKaul commented on code in PR #22050: URL: https://github.com/apache/datafusion/pull/22050#discussion_r3220215529
########## datafusion/optimizer/src/reorder_join/join_graph.rs: ########## @@ -0,0 +1,710 @@ +// Licensed to the Apache Software Foundation (ASF) under one +// or more contributor license agreements. See the NOTICE file +// distributed with this work for additional information +// regarding copyright ownership. The ASF licenses this file +// to you under the Apache License, Version 2.0 (the +// "License"); you may not use this file except in compliance +// with the License. You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, +// software distributed under the License is distributed on an +// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY +// KIND, either express or implied. See the License for the +// specific language governing permissions and limitations +// under the License. + +use std::sync::Arc; + +use datafusion_common::{DataFusionError, NullEquality, Result, plan_err}; +use datafusion_expr::{ + Expr, JoinType, LogicalPlan, + utils::{check_all_columns_from_schema, split_conjunction_owned}, +}; + +pub type NodeId = usize; + +pub struct Node { + pub plan: Arc<LogicalPlan>, + pub(crate) connections: Vec<EdgeId>, +} + +impl Node { + pub fn connections(&self) -> &[EdgeId] { + &self.connections + } + + pub(crate) fn connection_with<'graph>( + &self, + node_id: NodeId, + join_graph: &'graph JoinGraph, + ) -> Option<&'graph Edge> { + self.connections + .iter() + .filter_map(|edge_id| join_graph.get_edge(*edge_id)) + .find(move |x| x.nodes.contains(&node_id)) + } + + pub fn neighbours(&self, node_id: NodeId, join_graph: &JoinGraph) -> Vec<NodeId> { + self.connections + .iter() + .filter_map(|edge_id| join_graph.get_edge(*edge_id)) + .flat_map(|edge| edge.nodes) + .filter(|&id| id != node_id) + .collect() + } +} + +pub type EdgeId = usize; + +pub struct Edge { + pub nodes: [NodeId; 2], + pub on: Vec<(Expr, Expr)>, + pub join_type: JoinType, + pub null_equality: NullEquality, +} + +pub struct JoinGraph { + pub(crate) nodes: VecMap<Node>, + edges: VecMap<Edge>, + /// Non-equi predicates hoisted out of decomposed `Join.filter` clauses + /// and out of `LogicalPlan::Filter` nodes that sit between joins. + /// The enumerator must reapply these on top of the reordered plan. + filters: Vec<Expr>, Review Comment: I think the issue with keeping the filters on the edges is that they could also be rearranged during join reordering, which could lead to different results. By keeping them "above" the joins, the filters will always apply no matter the join ordering. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
