risingwave_frontend/optimizer/plan_visitor/
side_effect_visitor.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::{DefaultBehavior, Merge, PlanVisitor};
16use crate::optimizer::plan_node;
17
18/// Recursively visit the **logical** plan and decide whether it has side effect and cannot be
19/// eliminated trivially.
20pub struct SideEffectVisitor;
21
22impl PlanVisitor for SideEffectVisitor {
23    type Result = bool;
24
25    type DefaultBehavior = impl DefaultBehavior<Self::Result>;
26
27    fn default_behavior() -> Self::DefaultBehavior {
28        Merge(|a, b| a | b)
29    }
30
31    fn visit_logical_insert(&mut self, _plan: &plan_node::LogicalInsert) -> bool {
32        true
33    }
34
35    fn visit_logical_update(&mut self, _plan: &plan_node::LogicalUpdate) -> bool {
36        true
37    }
38
39    fn visit_logical_delete(&mut self, _plan: &plan_node::LogicalDelete) -> bool {
40        true
41    }
42}