mingmwang commented on code in PR #4122: URL: https://github.com/apache/arrow-datafusion/pull/4122#discussion_r1018051126
########## datafusion/core/src/physical_optimizer/enforcement.rs: ########## @@ -0,0 +1,2001 @@ +// 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. + +//! Enforcement optimizer rules are used to make sure the plan's Distribution and Ordering +//! requirements are met by inserting necessary [[RepartitionExec]] and [[SortExec]]. +//! +use crate::error::Result; +use crate::physical_optimizer::PhysicalOptimizerRule; +use crate::physical_plan::aggregates::{AggregateExec, AggregateMode, PhysicalGroupBy}; +use crate::physical_plan::coalesce_partitions::CoalescePartitionsExec; +use crate::physical_plan::joins::{ + CrossJoinExec, HashJoinExec, PartitionMode, SortMergeJoinExec, +}; +use crate::physical_plan::projection::ProjectionExec; +use crate::physical_plan::repartition::RepartitionExec; +use crate::physical_plan::rewrite::TreeNodeRewritable; +use crate::physical_plan::sorts::sort::SortExec; +use crate::physical_plan::windows::WindowAggExec; +use crate::physical_plan::Partitioning; +use crate::physical_plan::{with_new_children_if_necessary, Distribution, ExecutionPlan}; +use crate::prelude::SessionConfig; +use datafusion_expr::logical_plan::JoinType; +use datafusion_physical_expr::equivalence::EquivalenceProperties; +use datafusion_physical_expr::expressions::Column; +use datafusion_physical_expr::expressions::NoOp; +use datafusion_physical_expr::{ + expr_list_eq_strict_order, normalize_expr_with_equivalence_properties, + normalize_sort_expr_with_equivalence_properties, PhysicalExpr, PhysicalSortExpr, +}; +use std::collections::HashMap; +use std::sync::Arc; + +/// BasicEnforcement rule, it ensures the Distribution and Ordering requirements are met +/// in the strictest way. It might add additional [[RepartitionExec]] to the plan tree +/// and give a non-optimal plan, but it can avoid the possible data skew in joins Review Comment: Yes, correctness is always the P1 priority. Here the non-optimal plan means if the optimization target is to find out a plan which can have the least number of Repartitions and Sorts, then the current implement can't reach the goal. And need more complex algorithms. -- 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]
