xiedeyantu commented on code in PR #22370: URL: https://github.com/apache/datafusion/pull/22370#discussion_r3270247893
########## datafusion/optimizer/src/expand_join_or_predicate.rs: ########## @@ -0,0 +1,174 @@ +// 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. + +//! [`ExpandJoinOrPredicate`] rewrites inner joins with OR filters into a UNION ALL +//! of mutually exclusive hashjoin-capable inner joins. + +use crate::optimizer::ApplyOrder; +use crate::{OptimizerConfig, OptimizerRule}; +use std::sync::Arc; + +use datafusion_common::tree_node::Transformed; +use datafusion_common::Result; +use datafusion_expr::logical_plan::{Join, LogicalPlan, Projection, Union}; +use datafusion_expr::utils::{can_hash, find_valid_equijoin_key_pair, split_binary_owned, split_conjunction_owned}; +use datafusion_expr::{Expr, ExprSchemable, JoinType, Operator}; + +#[derive(Default, Debug)] +pub struct ExpandJoinOrPredicate; + +impl ExpandJoinOrPredicate { Review Comment: I see this as a relatively standalone piece of logic, and I haven’t yet found a clean way to hook into it. Another concern is that I’m not sure whether DataFusion can reliably obtain the row counts from both sides of a join—during testing, I noticed that when both tables are very small (say, ~10 rows), NestedLoopJoin can actually be faster than HashJoin + Union. However, once both tables grow larger (e.g., 1000+ rows), the rewrite shows very significant gains. Could you walk me through your concerns in more detail? That would help me figure out how to improve it. -- 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]
