risingwave_frontend/optimizer/rule/
project_join_separate_rule.rs

1// Copyright 2025 RisingWave Labs
2//
3// Licensed under the Apache License, Version 2.0 (the "License");
4// you may not use this file except in compliance with the License.
5// You may obtain a copy of the License at
6//
7//     http://www.apache.org/licenses/LICENSE-2.0
8//
9// Unless required by applicable law or agreed to in writing, software
10// distributed under the License is distributed on an "AS IS" BASIS,
11// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12// See the License for the specific language governing permissions and
13// limitations under the License.
14
15use super::super::plan_node::*;
16use super::{BoxedRule, Rule};
17pub struct ProjectJoinSeparateRule {}
18
19impl ProjectJoinSeparateRule {
20    pub fn create() -> BoxedRule {
21        Box::new(Self {})
22    }
23}
24
25impl Rule for ProjectJoinSeparateRule {
26    fn apply(&self, plan: PlanRef) -> Option<PlanRef> {
27        let join = plan.as_logical_join()?;
28        if join.output_indices_are_trivial() {
29            None
30        } else {
31            let (left, right, on, join_type, output_indices) = join.clone().decompose();
32            let new_join = LogicalJoin::new(left, right, join_type, on);
33            let project =
34                LogicalProject::with_out_col_idx(new_join.into(), output_indices.into_iter());
35            Some(project.into())
36        }
37    }
38}