risingwave_frontend/optimizer/rule/
union_input_values_merge_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::{BoxedRule, Rule};
16use crate::optimizer::plan_node::LogicalValues;
17use crate::optimizer::plan_node::generic::GenericPlanRef;
18use crate::optimizer::{PlanRef, PlanTreeNode};
19
20pub struct UnionInputValuesMergeRule {}
21impl Rule for UnionInputValuesMergeRule {
22    fn apply(&self, plan: PlanRef) -> Option<PlanRef> {
23        let union = plan.as_logical_union()?;
24        // !union.all() is already handled by [`UnionToDistinctRule`]
25        if !union.all() {
26            return None;
27        }
28
29        let mut rows = vec![];
30        for v in union.inputs() {
31            rows.extend_from_slice(v.as_logical_values()?.rows());
32        }
33        Some(LogicalValues::new(rows, union.schema().clone(), union.ctx()).into())
34    }
35}
36
37impl UnionInputValuesMergeRule {
38    pub fn create() -> BoxedRule {
39        Box::new(UnionInputValuesMergeRule {})
40    }
41}